It had a good build in pace of puzzle difficult and mechanic introduction and application. Everything is very possible with a difficulty to it to make it not frustrating but also not boring. The controls are pretty tight, sometimes the block gets kind of finicky though.
I really like the underworld changing up the directional buttons as well as the use of the momentum jumps with that gimmick. Sometimes I'd appear in the underworld with a ghost immediately on me, I wasn't clear on how to 'shake' it off, I presume moving back and forward, but I'd still get some annoying deaths from that.
I'd like a medal for not having to continue from a ghost death as well as killing as few enemies as possible. The two lizard/dragons in level 9 on the path up to the block are the only ones that'd be very hard to avoid, trying it I was only able to not kill one of them, while getting the block down. Just a thought though. Otherwise everything was awesome, I especially liked the last level...the real one.