I like the idea behind this one, but I found it to be a bit confusing to learn. It wasn't clear to me that I was searching for a key at the start, or where/what the doors were. I think you could have put the key at the start (in the light) of the first level to emphasize that that was the goal of each level. Feedback on unlocking the door would have also been nice for that reason. Once I understood that that was the goal it wasn't too bad though.