I agree a lot with SHfan84 and psymagic's review of this game. It's really an improvement of the former game, and I enjoyed it a lot.
I would definetly play this again, if I get the mood for shooting around. I also like that the difficulty isn't insane like it is in so many other bullet hell games, because I don't want THAT much frustration. I'm a casual gamer, regarding bullet-hell games.
It's not the best game, it could use minor improvements, however I give it 5 stars because it actually lives up to its purpose and expectations.