Enjoyed the minimalist game boy style graphics. The concept was easy to pick up and the limited inputs led to some creative problem solving. Also like the comments on each level.
The only real critique I have is similar to Zukoix's about tweaking the physics to be a little more forgiving so the player can focus on solving the puzzles instead of feeling like they're battling the physics of the game (boxes getting stuck, my head stopping me from falling, popping out a different side of the portal than the boxes).
Great job overall though!