I played it for the first time during 5-10 minutes but don't hesitate to ask me to test specific aspects of the game. I played the 3 first levels.
I very enjoyed firering differents kind of bubbles at enemies, the game mechanics seems flawless and pretty advanced !
But I don't like the grey circle mask around my character. Even if I was able to understand (I think) the aspects of the game quickly the way it is learned is complex and I don't think its because of the complexity of the game mechanics. I stop playing because I wanted to be able to launch fire balls everywhere wihout being stop by the interface (I don't know if that make sense) or learning the game.
My global thinking of it : it seem pretty fun and advanced, probably flawless in the mechanics and imo you can probably concentrate on the general visual aspect (specially of the interface) and a way to give to the player the mechanics of the game in a more fun way (like an inside series of events I don't know ?).
With the art aspect the simple pixel art is very ok with me, maybe too much greenish, brownish grey colors ? I want it more to look like http://mcpixel.net/ and I want to play it fullscreen x) but maybe its because I don't press the keys for it but generally I want to be more immerse in it.
I hope my feedback make sense and I think it can be a very fun game !