Nice game! The visuals are top notch, the ambiance is really nice. I liked the gameplay loop, simple but efficient ^^. I would have liked to do something with my cristals (like a shop or something), but that's quite a lot to ask for a 7-days jam. It's already amazing to have such a level, enemies with pathfinding and all that,the game is really polished (and the "B" button is an awesome addition!)
I had a couple of weird bugs, like a door I opened that lead to an unloaded room, made me fall in the void and respawn at the start, and also I went through a wall (that was door-shaped, I thought it was a secret passage xD) and also fell into the void. Nothing too dramatic, I didn't have cristals both times so it was just funny =p.
There is something I don't understand: what is the light jauge for? I thought I would die if it reached 0 but nothing happened (expect my torch particles turning off). Also, enemies one-shotting seemed a bit too harsh, since there are times I don't think I could have avoided them ^^'. Maybe enemies should consume light instead, and the player only die when the light is out (which is, I think, what the description says)? Am I missing something?
Overall a nice entry, congratulations ^^!