Fun Concept
There's a lot to like about this game.
The idea of a super smash brothers-esque fighter/defense game with construction elements is pretty innovative. I enjoyed the scramble to just build an area to stand on in time for the next level, dreading having it inevitably ripped out from under me. I found the character designs simple, very sinister (including the angels) and just varied enough to be entertaining until the end of the game. The music has a nice ambiance, is pretty catchy, and contributed well to the setting.
Now for the criticism.
The game got repetitive after a while. Though it was fun dealing with each enemy type in conjunction with the others, after I figured out their attack patterns it was pretty much lather, rinse, repeat. The jumping demons in particular were just annoying. Huge health bar, stand next to them and mash space. The most fun levels were early on when I had to actually worry about keeping the stage together and managing soul points. By the end, I had usually killed so many baddies that I could repair the whole stage without much effort. My last complaint is that there's no feeling of danger by the end. Perhaps a hard mode without the infinite lives? Maybe a survival bit?
That said: THIS IS A FUN GAME. All the criticism is just a request for some polishing. Keep up the good work!