Absolutely fantastic. I adore everything about this, from the perfectly emulated PSX palette to the crispy smooth music to the unique set of mushroom characters.
One thing I'll say about the gameplay is it's like if you took the difficulty of Stormy Ascent and multiplied by 5 or 6. The checkpoints are a bit more forgiving here than in Crash though so it's not as noticeable how often I die (and I died a lot). If anything maybe the hitboxes on some of the spike traps need slight adjusting.
This game's a true gem in the huge sea of PSX-like titles out there right now, and I'm very excited to see what comes of later development.