It's a great little game! Controls are tight, music and sfx are excellent, graphics are smooth and distinctive, the main character is super cute, and the puzzles are hard but fair. The map fills out as you explore, and shows all the details of the levels you need to see and the types of obstacle you'll need to get past. The puzzles do get difficult quite quickly, especially if you are collecting all the friends, but it subtly teaches you what you need to know and when you get through them it feels great, especially if you take a minute to think them through and then successfully implement your plan! I found it hard to stop playing until I'd finished it, and was very satisfied when I did.

Structure-wise, it's very much a traditional Metroidvania from a top-down perspective (so, Zelda?), with item X letting you get past obstacle X, and item Y letting you get past obstacle Y, etc. I personally would have liked to have seen Metroidvania progression in a style a little more like The Witness or Fez, where you have all the abilities already but just lack the knowledge of how to use them to progress, but I don't know how that would have best been implemented. Maybe that could be something for a follow-up game if the developers decide to go in a similar direction - I'm sure the block pushing mechanic has that potential. As is, it's full of charm and well-designed puzzles, and is well worth the time, money, and brain strain!