Very cool mechanic. Took me a while to figure out the second puzzle :D
I like the light indicator that shows you how much "energy" there is left on a tile.
It's cool that you already have many different mechanics in so few levels, the only thing now would be adding more levels (but of course that's out of scope for a game jam). Some additions I think would be cool: an indicator whether a level is already solved in the main menu (or lock later levels so you have to do them sequentially), and a reset button.