Nice game, I like how the camera moves.
Some ideas for improvements:
- Have the sight radius of the guards limited, sometimes you are spotted by a guard without even seeing them. (after the blue door)
- Have the keys vanish after using them on their door
- For the red traps, have some pre indication right before the spikes appear, like a red flashing
- Add Music (OpenGameArt has lots of CC0 tracks)
- Add Checkpoints (especially if you plan to make longer levels)
- "You have lose this level because... " should rather be "You have lost because..."