Fun concept! My favorite enemy was the one that grabbed the gems ahah. The drill one was super fast and hard to avoid. The idea is really cool, but I think you shouldn't have used "Boulder Dash without the Boulders" as it looks something different altogether (except for the theme).
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I'm also participating in the jam, it just doesn't fit because when I think about Boulder Dash I think about digging dirt and a player without gravity moving in tiles. You shouldn't remove if you don't think anything else that could fit!
The thing with the drill is that it hits me whenever I try to move long distances and it catches me off guard as its so fast. Anyway, congratulations for the fun game, its really amazing :)