The game is a lot of fun! The controls are tight and the platforming can get challenging! Furthermore, I love the use of the game jam theme. The only thing I would personally recommend is that the theme may be more impactful if when you died, you respawned in the alternate level at a similar location to where you died, rather than a designated spawn point as is the case here. As it is, the first goal is simply to die to get to the version of the level that is completable, while having you respawn near where you died in the alternate level would give death that requirement of skill since you could play around with having certain tunnels open in one level that are closed in the other, and vice-versa.
I'm very impressed by the game, especially its look and feel!