I have tried the demo , just one things to say : GREAT

The game have lot of colors , that makes it manga,toon or anime an it looks great like that.

just 3 points :
-you could have done some bigger levels ,
not with lot of things , but bigger to explore a little.
- i don't like the camera , caus it reacts to quickly as the player turns,
a camera that would rotate or move more slow with some aceleration
deceleration would be great like in mario 3D Game , or Zelda
caus the camera reacts too quickly, withut smoothnes like an FSP game
- your walls look too squarry like walls and not cliffs, perhsaps you coudl rework that a little.

appart from that , your game is really enjoyable , fun, i would want more ennemies in bigger areas ;
i have played another indie game : Fate and it looks more polished , i think you could rework the textures in some areas , and put some walls that would look better.

Your game really rocks.
Keep it up