For this being not only your first game jam, but also apparently your first time really making games this is actually very impressive to me. Not because it's the flashiest game or perfectly made or anything, but you avoided the single largest problem any inexperienced game jam participant can make; overscoping yourself. It's so deceptively easy to decide to make something you'd struggle to make on a normal time scale, let along a 48 hour period, and your handled that smartly. You sacrificed a bit on presentation, but it's paid off in quality; your game runs well and works how it should to the point that its design can shine through any presentation or coding quibbles. Well done!
As for critiques, there's all the obvious stuff; abstract shapes can only get you so far, the puzzles were a bit redundant, and some sound would have been nice. One very specific thing I noticed was that you left z-axis rotation on for your cube dudes. This isn't a bad thing and I can't see it affecting gameplay as it is, but It's something to be aware of if you were to ever introduce any physics-based elements to play.
All around though, great job! May this be the first of many games you make!