Pretty nice game!
The credits crawl could be a little less long, there is a glitch where with enough speed you phase through the ground (Yes I know it's known). And the not ghost is pretty useless, as the slimes while they can hurt the ghost are pretty easy to avoid.
Movement is pretty nice, and while collectables exist I don't quite understand how this fits in with the there and back theme.
I hated it but it was also the best game Ive ever played