I've seen other games with keys as entities but this one took it further which was good. I liked the alternative but worse controls if you get stuck. I also like the difference between yellow and green keys and the different options for your keys opening walls/healing.
I was disappointed that equipping the same key to multiple shoot commands didn't shoot in both directions at once.
Also the physics of the game was a little frustrating you accidentally dragged boxes with your feet a lot.
I also wish you had had time for some basic sound effects. But thus is a gamejam. Good job!