I didn't read the tutorial so I played most of the game in day mode. But then I changed it to night mode, and then somehow get stuck in a place where I needed a key to get out and stopped playing. Honestly, it's a decently made block-moving puzzle game without the day and night mode.
At first, it is not really obvious what the "up" directional block is. But eventually I realized that it can be imagined as a locked door. But it not a big work to draw a "lock" sign instead of "up" arrow. Then after a while of playing, I did learn that you can push the X gray block to cover a whole and walk over it. Since the game was made for a jam, I guess the game design is passable even at the current state.
When I get the hang of the game, I think I cleared almost all the room in the "III" level (to the north of the beginning level). There is a particular moment where I felt smart on figuring out the consecutive holes and locked door puzzle. Mind you that I did this all in day mode. That's why I think the night mode is redundant unless there's a cool lore behind it.
Another note, there seems to be a room where you can't possibly enter since it is blocked by red teleporters.
Overall, this is a decently made puzzle game and I enjoyed it