From someone who regularly breaks games, it's a pretty interesting concept! The first thing that comes to mind is definitely Rhythm Doctor's moving windows stage.
Transparency didn't work for me (Meaning black squares behind every PNG), unfortunately, and I didn't see the arrow hint in the first level. Ended up doing a jump while moving the window to avoid the second obstacle, cheesing it. I thought that was the intended way of solving it - the box being a red herring.
With that difficulty level in mind, I was actually excited at the game's puzzle potential on the next levels! Unfortunately, the subsequent levels are very easy compared to the first trick I pulled off, which was confusing until I saw the actual intended way of the first level.
The game introduces multiple mechanics in a single level - for the average non-puzzle enjoyer, this will confuse and frustrate them! On the first level, the game introduced doors, pressure plates, moveable boxes, moveable windows, and resizable windows whereas it could've started with only the moveable windows.
I'm wondering about the door, pressure plate, and box mechanic. It was only explored in the first level and nowhere else. Why introduce it if you're not going to use it again? It's a bit disappointing - it could've had so much application in the following puzzles, but instead, the number of mechanics seemed to regress consistently, which brings me to...
This is the case with the other only-moving-windows-around mechanic as well. While a safe space is provided to explore that mechanic, that is no culmination in what is taught. The last level could've been the first level, only teaching one mechanic, which is to move windows. And only then, teach the players new mechanics such as doors, moveable boxes, resizing windows and more, which will definitely make more sense.
All in all, cleared the game in ~2 minutes, and replayed it once.
That being said, controls are tight, music and sound are very good, the art is there, and it's still an interesting initial concept. It could use work from a design perspective, but that's alright for a jam, as I do not expect a polished AAA quality game within 3 days. :)