The ability tetris concept was really unique and interesting, and really well implemented. I'm always a sucker for cute pixel art and the colour palette was really pleasing to the eye. Audio fit the aesthetic very well, and you got a huge amount done in a small time.
I would say the controls and level design combined made for a very frustrating experience for me - I found myself over- or under-shooting every single platform, which kind of put a damper on my desire to explore the world, which seemed very well designed.
Still, a very impressive achievement, and I might try and make my way through the whole thing when I have more time and patience!