This is a pretty good one. An impressive number of levels for a game jam. My main feedback though is that the levels can feel a bit tedious or specific. For example, there are a lot of small and somewhat obvious things you have to do to reach the end, and often the levels feel like a collection of those. In puzzles (to me at least), it's generally better to have each level have its own "catch", or "seeming impossibility", and then a solution that communicates an interesting idea that makes you go "ooohhh that was clever". The solutions generally shouldn't depend on new information, but just seeing the given information in a new and interesting way.
That being said, this is still a cool game. Graphics and music set the mood nicely, and it's clear you guys put effort into this. I like how when one character dies they all fall, that's a cute little detail. And it was fun to learn the mechanics and apply them. I also like the fact that the levels teach you the mechanics as you go, rather than just putting text in the description or the start of the game, like a lot of other games.