Very fun, but infuriatingly frustrating. I don't even mean that by how difficult it was - that part, I actually enjoyed quite a bit. The game needs some tightening up. I liked the concept of this game - where the boss battles WERE the game, not just part of it - and the humor was fine, but the cutscenes... Man, the cutscenes killed me. They were often times longer than the battles themselves and the skip mechanism was slow and ineffective. It was, at times, almost impossible to navigate the menus because it would sometimes not allow me to click on the menu options for a brief moment. It would have been nice if you could have added a "Skip Dialogue" button that could have skipped the texts that I've read 30 times. Oh, and how great would it have been if you had tied most of the mouse-necessary interactions to keyboard shortcuts? Having to reach over to my mouse really broke me from the experience EVERY time I did it. It bogged things down. If you are to make a sequel, I suggest streamlining the game as much as possible.
Not to only complain, I did have enough fun with the game to play it to completion. It was simple, sh'm'up-y, bullet-hel-lite, upgrad-y, all that good stuff. I would recommend this to someone, if only to see what they'd think about it.
Post Script: An example of what I feel could have been tied to the keyboard would be the Store. Why wasn't I able to navigate the Store items by pressing the left and right arrows? Would have been a hell of a lot easier than clicking on a 24 by 16 pixel box each time, then moving the mouse over to the buy button. I binge bought most of the items in that store (I discovered it a bit late into the game) and that small action REALLY got in the way. Sorry for making this Post Script long, I'm just trying to get you to understand.