In order to do good at the demo run, there are a few strategies that can be used to save some time and skip some sections and puzzles:

1. Putting down and picking up Head usually has an animation during which you can't move. If you are in the air while pressing the pickup button, it is possible to basically skip the animation and not lose momentum.

2. After pulling the rock above the lake, you don't need to swim around at the bottom, you can just jump over it and then push from the other side to save a few seconds.

3. The first puzzle with the Airhunter larva (that is the little worm that the monkey-like creature wants to reach) is solved by giving the larva to the Airhunter, which can happen off-screen and will still trigger the animation that clears the roadblock. You need to be careful not to rush this section too fast though, as it won't work if the roadblock is in camera range before the Airhunter picks up the larva.

4. You can already move left while the camera moves back to the character after the cutscene where the drill breaks through the wall. This saves about a second.

5. You can use the first helium tank to float directly to the path on the right by gradually releasing air so that you land right on the ledge. This way you skip the entire upper area, which saves at least 30 seconds and skips 2 puzzles.

6. You can deflate Head with the deflate button to get below the water surface faster. If you don't fully fill up Head at the air tank before the lake and then time your deflation right, you can get below the surface and up to the Helium above the lake without losing any momentum.

7. The puzzle where the Airhunter usually needs to carry Head across the ceiling can be solved a lot quicker by putting Head near the right edge of the lake, then climb out with Body, jump and slightly move towards the edge, then press the pick-up button. This allows to get Head out the water by using the extended grab range in the air and if you time it right, you can hit the edge to pull yourself up again. This saves about 15 seconds.

8. After freeing the elevator, you can exit the elevator to the right while it is crashing down, so you don't have to float up again to get to the dark area.

9. If you know the path, you can navigate through the dark area without having to get the glowbee first, which saves at least 5 seconds.

Additionally, it is always possible to not fully fill Head at an air tank and still make it to the next point. Optimizing the fill amount for each air tank can definitely save a few seconds in the long run.