Do these pieces make a fun game? So far, yes. I'm on level 6 of 21 and hope to finish this weekend.
As far as I can tell, however, the story is just as ludicrous as I originally thought last year. The license adds nothing.
I really enjoy the game, but that's because I played the first half of it co-op with my brother.
We found the learning curve rewarding because we were sucking incredibly at first, but as we started learning the timing , and the combo system our enjoyment of the game grew considerably.
Each of the enemies has distinctly different ways of optimally beating them, and keeping track of what's going on around you, to limit the amount of time you are open for attack, while dodging intricate bullet hell patterns ... it pretty much captured my favorite parts of both it's component genres.
The characters also play considerably differently, so it's very replayable.