Played to the end and had a good time. Simple and fun jigsaw puzzle game with a twist, nice work! I usually quite despise jigsaw puzzle games as they are usually quite boring (there are some exceptions, but not too many), but I think your game is quite fun to play! For a starter, the puzzle is not that large, only 2x4 for a door, which makes the pacing really well. Each twist also feels noticeable enough to make each level feel not repetitive. The pixel art is also extremely well drawn and fits the game nicely. Overall, I quite enjoyed the game, and it's quite well done indeed!
Other things I like:
- Different unique elements for each door
- The door looks different too
- Beautiful end screen
Suggestions:
- The dark level has a lot of downtime waiting for it to turn bright again. Maybe doing some gradient darkening, I guess? Anything that reduces wait time is a win in my book
- A super nitpick that it would be nice to open the door at each level when pressing it
- More levels!