So, disclaimer, I haven't actually played the game, I've only watched a playthrough of this game through a Discord stream, so I'm going by what I've seen.
This is definitely a big coding feat, it must have been a lot of effort making an effort coding all this in Ren'Py so props to that. Now, when I first saw the first two levels being played through, I was like "Oh, this looks fun. I enjoy puzzles more than the average gamer. This looks right up my alley." And then I saw the third and fourth maze, and I was like "Oh my God, how the hell is any sane person supposed to figure this out by themselves?" I think the puzzles in this game are a bit too complicated for a game made for a non-puzzle-oriented jam. I especially think the method of getting the true ending normally is too cryptic for most people. I get it because it's hard to make a good puzzle game, and this one definitely made a good effort, but flew too close to the sun in some areas.
As for the story, it's alright. I like Gabriel; he's a pretty peppy guy in a strange situation. The memories were also neat vignettes, and the true ending was sweet. Unfortunately, the characters aren't that memorable or well-developed, which might be because the focus is on the puzzle sections. The CGs for the sliding puzzle look good, and the music selection is decent. Sorry if this is a bit disconnected, but it's hard to collect my thoughts for this game. Overall there were some good ideas in here, and while some of them fell flat, you certainly did a good job regardless.