Glad you liked the game!
wall jump was an unintended feature (but I forgot to remove it!). The puzzles can be solved without having to wall jump.
I definitely should've made it clear that the player can double jump, thanks for pointing it out!
You can use 'R' to restart the level if something goes wrong, like when you fall down the level.
Spoiler (solution of the elevator level) -> Once you get the player over the wall, you can quickly seperate and then fuse (S and then F) before the player touches the spikes, that way you will be fused but still fit in the hole and respawn after touching the spikes. You can then use the fused blob to push the box and finish the level.