I see everyone pointing out that the green gem was a bit overpowered and, I mean, it was, but I'm not one to hop on beating an already dead horse, so instead let me come at you with something slightly new; a good way to fix the green gem problem without scrapping the idea entirely might be to give it a limited range of movement, such as along a pre-defined track or within a certain radius. It's a sign of quality though that a jam-level game's two biggest notes from me are "a little too easy" and "kind of finicky." Well done!