Really fun! Very Celeste in all the best ways. Movement is fluid and fun to execute (though grapple is clearly way better then the other two), the size of the world is impressive for a jam game and I loved the boss fight even though it was quite difficult.
The one issue I have is that once I found a path I liked, since death is so punishing I didn't really feel like exploring other ways (though I did enjoy finding the easter eggs (the cool way of course) ).
Overall super fun and impressive!