Love the art style and the music. However the engine is a bit sloppy and at times just plain unfair. To clarify what I mean by sloppy, I've witnessed one of those normal skeleton enemies leave their platform and walk on air, I believe it was after hitting me, and with the giant Skeleton boss you don't even know you're injuring it until it dies. When it starts to flash before it dies it will do that forever if you keep on attacking, too... I had no idea at first that I'd actually defeated him. Those indestructible dog things just ruined it for me because their movement patterns, while able to be turned around, are just too random and the gaps between them too unforgiving for the floaty jump engine. The atmosphere was near on perfect, though, and I can't commend the art style enough! It's just sad for me to say that I felt the engine made it too hard to appreciate properly.
Okay, I just watched the walkthrough and it turns out you can kill those dog things, so forget about that particular comment. I swear I hit them way more times than that, though!