I love the mechanics of this game, and the backstory for it is adorable too. Having the short and tall character with different abilities reminds me of this old german GBC game called Die Maus.
Your game is a bit short, which is a shame because it feels like there's a bunch of cool potential levels you could make with the mechanics you've already got.
Solving 3D puzzles with only two 2D views is really creative, although it felt a bit like the tutorial level needed more... tutorial? I spent the longest time stuck on that, and found the other two pretty easy once I'd got that down. Maybe an EVEN easier level for the tutorial, and some help text to let you know what to do.
And then more more more! I want morrrrreeee :D
(-Joe)