This isn't exactly a guide, but it's things to watch for while running any of the levels, or how to do tricks if it has any.

Level 1:

• Make sure to keep an eye on the time it takes to load in to the level. If you're losing .2 seconds to Level 1, load into the level, exit, and go back in. Should be faster loading the second time around.

Level 2:

• The whole level is basically just a mashing test, so my only tip is to jump and enter the blob one tile higher.

Level 3:

• If you hold jump at the edge of the ledge, you can barely reach the slime blob over the pit. Saves a slight amount of time, and also some finger health. It's pretty easy, but if you're worried about it, not doing it isn't the end of the world.

Level 4:

• You can leave the goo one tile earlier and still reach the button if you hold left a bit.

Level 5:

• If you can mash fast enough, it's quicker to mash through the top layer of goo when going for the button.

Level 6:

• With a high enough jump, you can skip some of the bottom tiles.
• It's important to try and aim to hit the orange button as left as you possibly can.
• An easy timing for the last jump (for me at least) is jumping right in-between the third and fourth blue block from the left. It could maybe be faster to jump and mash right, but it's not that worth it unless you are just absolutely insanely fast.

Level 7:

• The box doesn't need to be ALL the way right. You can go a goo tile less and still have a clean few jumps to the door.

Level 8:

• It's basically just solving the puzzle but fast. Make sure to get the last right press in, it's common to miss it.

Level 9:

• You pretty much just mash for most of this one, but if you're not that fast of one make sure to fall a bit further. Landing on the bottom row is fast enough, you won't lose too much time doing it.

Level 10:

• This is the only level (so far) with a button skip. To do it, first make it to the second box, then position that box medium-right on the uppermost 3x3 square. With a well-timed jump, you can reach the goo on top, or you can fall down to the lowest layer if you want. No extra platform necessary.

Level 11:

• This one doesn't have a way to skip the bomb on rails, so you can take it easy until it goes left enough for you to push the box down. Classic fast mashing from there.

Level 12:

• This is basically an autoscroller, the only timesave is jumping as early as you can at the end. What works for me is jumping right at the second line in the wall from the left at your level, farthest right on the platform.

Level 13:

• You can completely ignore the normal crate, keep in mind that if you push it to the right after the laser is blocked it's a reset.

Level 14:

• If you're an absolute gamer, once pushing either crate into position, you can go right once, eject, hold left, and barely reach the goo without touching the ground. Saves time and feels good to do.

Level 15:

• Every box movement matters on this level. First, push the metal box right once, and push both wooden boxes once in the direction they're already pointing. After that, do the normal schtick of blocking the laser, and take the box with you to the left again. Position the reflective boi above the box you pushed down earlier, push that one left one, and the other two boxes up three times. Eject on top of the reflective box and make your jumps to the button and door.
  • It's a lot less confusing when just watching a top-level run, you'll get a better hang of it.

Level 16:

• If you mash up fast enough and enter the goo at the right spot, you can skip waiting out the first cycle. It's a risky move, though, since there's risk of explosions.
• You can do something similar at the end, though sometimes it'll be impossible depending on how you played the rest of the level.

Level 17:

• All about mashing in a set way three times in a row. Doing it fast is really hard, but just get in a groove and stay in it. No gimmicks here.

Level 18:

• Similar to Level 17, except it's four times, and also not the very end of the level. When doing the final box, DO NOT mash up too much, or you'll have to reset.

Level 19:

• Just beat the level as you usually would, but fast. Mashing the lines can be pretty tricky, so try to limit the amount of times you press a direction when in the middle stretch.

Level 20:

• This level has a really cool box skip that saves a few seconds. To do it, you just have to jump at the right time and press Z close to frame-perfect. For this one, just watch a normal run to get the idea.
• Other than that, it's pretty much just beating the level normally while mashing fast.

Final Room:

• Idk what you want me to say here, just don't mess up. :)

While watching a top run would give you a better idea of how to run the game, this'll be good enough if you don't want to do that. If you're unaware of the best strats for just one or two levels, you can watch one of the top IL runs instead of finding it in an Any% run.