Kinda like a rough crystal. There are a lot of great ideas. Graphics are great, and the gameplay idea is really nice. But it lacks a little tutorial of some sort, a timer/turn counter and maybe more diversity in the level design to become the polished crystal itself. However, for a game jam prototype this is really great (and a bit difficult !). 

Would be fun to expand the game a bit outside of the jam to see the possibilities :D

Nice treatments on the backgrounds! Collision map is also interesting technique.