If this had been a 48 day rather than 48 hour, I'd expect the next steps to be more systems, perhaps with more complicated minigames. I liked the sense of lack of control, but not the sense of lack of information. An instruction manual for how the laser system worked might be helpful for example. I died once partly because I didn't realise it drained faster as the game progressed.
Great job!
Edit: Also, WASD is a much better keybinding set than arrow keys.