This game has a really cool concept but simply isn't developed enough to be engaging.
My biggest problem is how easy it is. The life counter resets every fight and even when I get hit(which almost never happens because the random cannons can't hit the broad side of a barn) it only registers half the time and the auto-fire as well as the bosses constant swaying keeping it in range makes it so you don't even have to move to beat every boss. I've literally cleared twenty levels while I was writing this.
I think the game has real potential but, as it stands, its just not any kind of engaging or challenging and is barely even playable.