So glad I played it. What a gem of a game. Truly worth even if asking was full price.
It's huge, varied, interesting, fun, tough, and most of all, truly engaging. The platforming is sick. Boss battles are glorious. If I have a complaint, it's that the map is just too big. Game would've been better if it were tighter.
There's enough intelligent bits to make you go "mmmm clever" every once in a while, and optional platforming areas to make you feel like an orchestra conductor once you get the flow. Still, you can complete the game without being nosey about the world at all.
Remarkable.
9/10.