Tower of Heaven is utterly fantastic. It plays solidly (although for such a purposefully retro game it requires an awful lot of resources) and turns the whole established platforming formula on its head. Learning new rules is so different, so interesting, and so-much-fun. I loved every minute of it.
People complaining about the difficulty are simply too set in their old ways to accept this new style of gameplay. It's not hard at all if you follow the rules! At least...it shouldn't be hard for any Super Mario World vets.
The music is SO good. I haven't been this impressed with a chiptune soundtrack since Cave Story. Really flashygoodness, you've outdone yourself. The way the theme is incorporated into every piece without sounding repetitive or uninspired is REALLY impressive. A++.
Long story short, this game is wonderful. Anyone who enjoys a good oldschool platforming romp with new twists, great music, and solid design owes it to themselves to play through this one.
10/10, A++, 5/5 stars, etc.
It really would make a fantastic XBLA/PSN/WiiWare/DSiWare game...I'd pay upwards of $5 for it AS IS, and up to $15 for new levels, rules, and music.