Absolutely amazing!
This has so much content, and so far the levels I've played have been pretty well balanced too, with a nice difficulty curve as you get further. The only issues I've encountered is that some animations don't reset (bossfights mainly) which means you may start in an already dangerous path. But generally, it's been pretty smooth too :)
Sadly I left the game alone for a bit too long so it reset to the initial slide. But man, this must have required so much dedication - I'm very impressed.