Eternal engine is the last mech stage of hero story. Times are somewhat divided up by platform cycles, as the platforms after checkpoint 2 have certain parts of their cycle in which you cannot enter or exit the cycle. The fastest time known to be possible in a run is a mid 1:57, however with very optimal movement, and the use of many precise tricks, it might be possible to make an earlier platform descent cycle (or half cycle), which could potentially land times as fast as 1:54. At the moment, half cycle is only hypothetically possible. Runners with average mech stage skill will usually make the second cycle, which can land times as low as 2:06. The current route of the stage uses a clipout to skip the majority of the stage.

Eternal engine skip/ clipout methods

Eternal engine skip is done by abusing the mesh of a tank near a wall to clip out of bounds, while out of bounds, the player will be much higher than the goal of the stage, allowing the player to hover behind the goal ring and toutch it from out of bounds. Done properly, this skip saves roughly 50 seconds.

Clipout methods

1. Door clip: This method abuses the door opening next to the tank to force tails out of bounds. In order for this to work, the mech must be facing forward against the wall and slightly to the right, and it must partially clip through the wall at the same time the door opens fully, you must be holding forward and slightly right on the control stick to partially clip throuh the wall. Two things are needed for this method to work, angle of the mech, and timing of the partial clip through the wall. There are setups that will always time the partial clip correctly, making the mech angle the only factor to worry about. It is recommended that you practice this with an emulator, and put a save state right as you come out of the platform cycle. Practice it until you find a setup that always gets the partial clip timing right. This is by far the easiest and most consistent method of clipping out, as well as the most recommended and widely used, with some people managing to successfully clip out with a >95% consistency. The average runner usually sees a roughly 40% consistency with this method knowing only about the angle to hold.

2. Instant clip: This clipout basically involves mid jumping into the edge of the tank, holding the correct angle, and hoping it works. There have been setups for it that improve consistency, but they take a while to setup. While this method can end up being over a second faster than door clip, it is much harder to perform consistently. Some very good runners can pull this trick off quickly with a >50% success rate, but it will require hours of practice with a savestate to achieve even 50% consistency. If the instant clip fails, and the door is also triggered, it is sometimes still possible to clip out using the door. While technically the fastest clipout strat (by about a second), it is not very widely used or recommended.

3. Backup door clip: If you miss any form of clip, you can wait for the door to close, and hover slightly over the middle of the tank and quickly get back into the corner position after activating the door. This is tricky and especially tough to get the correct partial clip timing correct, so it is rarely used, but if practiced heavily, this is a better alternative than other ways of resetting the clip.

Out of bounds travel methods

After clipping out of bounds, you will be much higher than the goal ring, and will need to travel roughly back and right. There are several methods of OOB travel, with varying difficulties and resulting times.

1. Beginner method: after clipping out, and as soon as the camera changes to show tails, start hovering back and mostly to the right. Finding the right angle to hold takes practice and experimentation. at somepoint, all of the parts of the stage in the background will completely unload. Don't worry, keep going, in a couple more seconds, you should appear in front of a large concave green wall with a smaller green cylinder. the green cyclinder is the last part of the stage. if you aren't comfortable with hitting the goal ring from out of bounds, you may clip back into the stage by flying into the green cylinder and completing the stage the normal way. This is much slower and not recommended. in order to find the goal ring out of bounds, go right behind the green cylinder (to the left of it) and drop. there is no need for a slow descent, as you will land on an invisible platform. The goal ring is now right under you, walk backwards off of the platform, then hover back under it. You should see a shape with vertical red lines, hover right into the second red line from the left, and descend while holding forward right, you should hit the goal ring.

2. early drop: after you become more familiar with the position of the goal ring, you can start your descent to it's height sooner, forgoing the use of the invisible platform as a guide. this saves time, but there is a risk, as you need to know when to start the drop, and when to start hovering again. Finding this takes practice and it is recommended to use savestates to practice you OOB travel. Other things to do to optimize your OOB travel, find the most direct angle to hold to get to the goal ring. for this, it is recommended that you stop using the background as a guide, and instead, measure the occlusion of the mechs left leg fin. Keep experimenting with different angles untill you know exactly what angle takes you to the goal. Optimally, you would constantly be adjusting your angle to accound for the camera angle shifting, but this takes a lot of practice to master and is recommended as the very last part of the stage to be optimized.

3. Jazz method/ drop from the start: this method is technically not faster than an optimized early drop method, but it completely removes the guesswork of when you should drop and when you should start hovering again. It is essential that you fly at the correct angle for this to work, or else you will be too low. As soon as you clip out of bounds,  right and start hovering for a bit(before the camera change), this is mainly to redirect your momentum. then release the hover and hover again after the camera changes. Now hover back right until you pass through the first wall, this is where you will perform the early drop. Drop to a predetermined height, using the background as a reference. (the way Jazz does it puts you at a height right below the invisible platform and above the goal ring). Now you must hover at a precise angle, using the left leg fin of the mech as a guide, measure the occlusion. The fin should be bobbing up and down slightly behind the top corner of the left foot of the mech. If all goes well, you will fly right to the goal ring, and all you have to do is release your hover as you are about to pass over it. You might have to make very slight adjustments to your flight angle depending on your position as you pass through the wall and set up your height. This strategy is very difficult to learn and might take a couple of hours of experimentation before you get it down. It is recommended for expert players.

4. camera curve negation method: This is the newest method, known to save over a second if done optimally. While travelling towards the goal ring, the camera slowly curves to the right, meaning if you hold one angle the entire time, you will actually be travelling in a curve. Obviously the fastest way to go from one point in space to another is a straight line. we can't perfectly cancel out the curve of the camera, but we can do our best to estimate. To do this method, start traveling more to the right than you normally would, and slowly curve around until you are facing almost forwards. If you do this right, you will end up right over the goal ring at the end. This is sometimes more of an art than a science and requires a lot of practice to get the feel for it.

Beginning to checkpoint 1

The start of the stage is one of the trickiest parts to master. You must lock on to both beetles in the first room to open the door. The fastest way to do this is to hold a slight angle towards the beetle on the right as you fall, and start targeting it. As soon as you target the beetle (happens offscreen) release and target the next beetle. The purpose of releasing your targeted attack before locking on to the second one is twofold, firstly, getting the first shot fired off as soon as possible, kills the enemy as fast as possible, secondly, if you fire off both shots in a combo, the second shot gets delayed slightly. After destroying both beetles, the door simply will not open fast enough for you to run straight through it. The easy way to allow the door to open in time is to hover in short bursts as you target the beetles, however, the fastest way is to do a mech juke after firing at the second beetle. In order to do this, turn your control stick around CCW as you target the enemies, then pull forward once your control stick is pointing all the way back. This juke move give the door just enough time to open, and gives you the most speed while passing through the door. Recommended if you want to save frames and look like a TAS.

After passing through the first door, immediately target and destroy the robots down the hallway as you run down. Your main goal here is to take out the carpet bombing robot. making it through the next door while maintaining full speed is very difficult and precise. it is recommended that you use the patterns on the floor as a visial cue for turning, and do a short hop to slow you down just enough to allow the door to open. Remember that sharper turns lose speed, try to find the widest angle you can for this door.

As you pass through this door, start targeting the two beetles at the end. They can be tricky to target because there is a lot of clutter that you might target instead, so practice finding the right angle to hold. Just like the beetles at the start, you don't want to chain these guys in a combo. releasing a shot before targeting the next one will kill them both quicker. all you need is a quick release and repress of the B button in between lock-ons. If you kill these beetles soon enough, and are properly positioned, it is possible to walk directly through the door without slowing down, but this is rare, you should do a very short hop in front of this door if you don't want to bonk into it.

The next room has two pulleys and a bombing robot. If you go to the right side of the boxes with the spring, and jump into the side of it, you will clip the spring, saving time. As you go up the pulley, keep in mid that if you did the start fast enough, the bombing beetle might obstruct your path to the next pulley (you can actually go fast enough for this to not be an issue) If you think this robot might be in your way, it doesn't hurt to shoot it down. Now hoverjump over to the next pully, the sooner you perform the hoverjump and still grab the pulley, the better. as you take this pulley up, go neutral on the control stick and start aiming your laser. The camera will change to show bomb carrying robot, as soon as you lock on to it's main body, release your shots, then hoverjump while holding forward and slightly right. your should have just enough height to make it on to the next platform, and the enemy will be destroyed before it get's in the way. now run forward  and wait a bit before shooting the next enemy, if you don't you might hit one of the explosive green capsules, which causes the camera to shake violently, making it harder to see during the next set of doors. Try to line yourself up with the part of the door that opens first. in all likelihood, you will need to do another short hop before this door so that you don't bonk into it.

Hitting the checkpoint is optional, and wastes a few frames, which may be negligible.

Checkpoint 1 to checkpoint 2

This part of the stage is possibly more tricky than the start, and also more dangerous. To pass through the first door in this section, jump at an angle towards the door's opening as soon as the door is activated. Jumping retains more speed than sharp turns. it is also possible to take a wider turn through this door, but it isn't really any faster. Do whichever suits you best. The next room is simple, stay to the left of the lasers ahead, and be aware of your fins, don't let them clip into the lasers. after passing the lasers, try to angle yourself right to where the door opens, you might be able to pass through this door without a short hop, but it's precise. shoot the bomb carrying enemy and prepare for the infamous chao box room.

Chao box room

That's damned right, this room deserves a section of it's own, because there are many different strats for it ranging from easy but kind of slow, to mech movement gods only, also, this is probably the most movement intensive part of the stage. There are boxes in the room, one of them is a chao box, all of them are in the way of the switch. There are also some dynamite packs that you do not want to trigger or else death may occur. The switch you need to activate in the room sometimes doesn't like to cooperate. If you want to break all of the boxes without hitting the dynamite, you can shoot through the door before entering the room. Just send in several shots and you should be good. When the chao box is broken, for some reason, this sets your speed to 0. this isn't that bad, because you need to wait for the door to open anyway, but it isn't the optimal way to pass through the door. Let's look at some possible scenarios when you go through that door.

1. every box is broken, the chao key is exposed. Run straight to the switch, hop over the chao key, juke, hop over the chao key again, move to the left where the door opens, and hop through the door at an angle that takes you straight through the next door. There is a decent risk of picking up the chao key here, which loses a lot of time RTA. (no penalty in an IL).

2. every box except for the one above the chao key was broken, the last remaining box blocks you from grabbing the chao key. This is pretty much what most runners want. you can jump onto the box, fall on the switch, juke, hop back onto the box, and position yourself to hop through the door and run straight through the next door.

3. all boxes are still intact. You should jump over the box on the left, land on the switch, juke and turn to the box on the left, shoot the box before running through it, then go through the door. This movement is tough, so you probably want to avoid this situation altogether.

Lets say you want to enter the room with more speed. You can't break the chao box because it will bring you to a full stop. after taking out the bomb enemy, you want to shoot a carefully placed shot through the door into the box on the left (requires a lot of practice). then do a short hop to avoid bonking on the door. You now have to go around the left side of the boxes, and run into the switch, juke and maneuver back around the boxes. this should set you up nicely to just go straight through the next two doors, but you still might need to short hop before leaving the chao box room. This movement is very tough, but earns you a lot of time, and is fully necessary if you are going for the legendary half cycle. This is even faster than the standard IL method, but really only recommended for the truly determined half cycle hunter.

Post chao box room

Now that you've escaped the nightmare that is chao box room, you must proceed over a narrow bridge with dynamite packs and a bomb enemy. You can quite easily shoot the bomb enemy without setting off the dynamite packs, assuming you don't have the laser upgrade. right as the next door starts opening, hop right in front of where it opens, this is the most reliable way to conserve speed here. The next room is simple, line up with the door's opening spot, and to a short hop right as you pass the last dynamite pack. Do not shoot anything.

Next, you must fall down to the platform below. The sooner you fall down there, the sooner the rocket starts activating, however, sometimes jumping right over the edge results in your camera getting stuck, if this happens, hover a bit before you land and hope it fixes itself. As soon as you enter the missile's activation range, it takes about 3.5 seconds to activate. There are several options here.

1. stand on the button and wait for the missile to fire, as soon as it fires off, hoverjump to the next platform.

2.count the time it takes for the missile to activate, and time it so that you run over the button and hoverjump as soon as the missile becomes active, This gives you more speed and makes the gap a lot easier to clear.

3. perform a juke over the missile button right before it becomes active, also gives you more speed and makes that jump easier.

4. go full TAS and time a juke against the wall and run over the button as soon as it becomes active. This gives you basically fullspeed and makes crossing the gap free.

there's no shame in pause buffering this particular hover jump. Otherwise, this gap can be a run killer for most people.

once you land on the moving platform, if it is going forward and you think it is about to turn, try to hoverjump off of it immediately, as you lose a lot of speed the platform is moving backwards. If the platform is moving backwards, try to hoverjump off of the end of it.

If it is moving forwards and not about to change, run to the front and attempt to hop onto the far edge and hoverjump off, this gives you the most speed.

The important thing is to try and make it over the cages with your hoverjump.

Falling weight room

The standard strategy for this room is to short hop in front of the door, destroy the tank at the end of the room, hover over the weight's shadow to avoid triggering it, and drop on the switch after you reach the far wall. You can then jump and clip into the spring on your left. This is a fast and safe method of progressing here, and it is recommended for anyone going for first or second cycle. 

The risky method (known as weight hop) involves skipping the deactivation switch, hovering right over the shadow to the spring, hovering towards the pully at the climax of your bounce (mainly to redirect your momentum), then jumping off of the weight as soon as you toutch it and grabbing the pully. This saves .60 seconds over not using it, but it is risky and hard to pull off. This definately requires a lot of practice to master, it is reccomended to practice this in an emulator with a savestate untill you can get it consistently. This trick is only recommended if you think you might need it to make first cycle, or if you are hunting half cycle.

All that's left now is taking the pullies to the checkpoint. You can jump off of the second pully a bit sooner than you might think, if you do a full jump off of it at the right time while holding forward, you will clip on to the next platform with the checkpoint.

Checkpoint 2 to skip location

Dealing with the artificial chaos enemy

The standard strategy for dealing with this enemy and opening the door is locking onto it, running up to it, and performing a propeller punch. This will kill it no matter what state it is in. This method is recommended for most runners because it is consistent.

Chaos quick shot

This is a way to kill the artificial chaos enemy without coming to a stop. as you enter the room (only works at fullspeed, so don't expect it to work if you bonk the door) run slightly to the right of the ememy, as you approach it, jump and turn to the left. during this jump, as you are facing the artificial chaos, shoot it in the face with a bullet. If you do it right, you will kill the enemy without losing much speed at all, and you will be facing the opening in the door in such a way that you can run right through it. This trick saves .60 seconds and is recommended if you think you might need it to make first cycle (if your checkpoint time is >1:06 ), and it is most certainly required if you are hunting half cycle.

The next room is simple, There is an artificial chaos, simply shoot it once with a lock on and it won't be able to hit you as you run past. then don't hit the lasers and do a small hop in front of the door. next is the platform cycle room.

Platform cycle room

at this point, you should quickly observe the platforms, are they rising or falling, can you reach them with a hover jump or not. You need to decide quickly. you can make it up to the ledge with a good hoverjump. it is advisable to pause buffer it. If you aren't comfortable with hoverjumps, you can hop on the boxes to the right or left, this is obviously slower.

The cycles themselves behave as such: your limits are whether or not you can make it on to the first platform, and whether or not you can make it out of the cycle. In between every normal cycle, there is a small window of opportunity where you can catch the platforms on the way down and make it across with pause buffered hoverjumps off of the railings of the platforms. These are the down cycles, or half cycles. you can also make it through these cycles by shooting a balloon to gain height and hover across, but that is slower than actually making the down cycle. During upcycles, you need to be careful, and make sure you can actually make it onto the cycle before attempting it, or else you could die.

There is a cycle that hasn't been reached yet, the down cycle before 1st cycle starts. considering how some runners have been too early to make it out of 1st cycle before chaos quick shot was discovered and weight hop was used, it seems that 1.2 seconds of timesave might be able to win you a down cycle, or a half cycle before 1st cycle. If this cycle is humanly possible, it will be very tough to get, will probably require all of the fastest strats mentioned on here, and could perhaps land times as low as 1:54