I really like the concept. A real brain scratchier. I do feel like the implementation could be improved slightly. The timings on the doors are really tight. I feel like they could be open for maybe a second more. Even if the player isn't pressed up against the door to set a checkpoint there they should probably still be able to get past. I feel giving the player some extra margin dose not remove from the puzzle aspect. I personalty was squished thru many of the doors. Outside of that I really like how clearly things are conveyed to the player. You can clearly see which bullets you have and the order and the buttons all have clear lines that show what door they open. Great game!