My Impressions:
*May Contain Spoilers*
The game is amazing
Presentation is top notch. From the first time I took down the 2nd stage boss, to seeing the 3rd stage boss blow up a bridge before the showdown. Also the setting is cool. You're not a lone fighter. It seems there's tanks on your side fighting for the cause as well (although they're not interactive nor do they actually help). It's just a nice touch I rarely see in other games.
controling the heli is really intuitive (I'm using reverse). It becomes second nature in no time.
the hit box takes some getting used to, as does maneuvering the heli in between bullets, but it'll come easy as time goes on (took me an hour or so)
the music is great, I switched between arranged and arcade, but I prefer arranged
graphically, I'd say the best looking 3D shmup I've ever played
it may not have the creative fantastical (I don't mean like Galuda) setting of Ikaruga, but the 3D models are plain awesome. Raiden III should have looked like this.
Attention to detail makes you wonder how much time those guys spent working on this game.
bullet patterns remind me of some psikyo games, are there former members with GRev?
now the cons:
play area is small, doesn't seem like a problem at first but there's an invisible wall blocking your heli from the left/right and top/bottom of the screen
You can't go all the way up (you actually stop quite a distance from it) and the bottom seems to stop right at the tail of the heli (the hit box is the cockpit, so you have a bit of room there)
The left and right area restrictions can be frustrating as well
you'll find yourself trying to dodge bullets but instead being stopped by the invisible wall and getting shot down
rank is a bitch, but if you've played a raizing game or two, then this shouldn't bother you much. It's just a learning process. I've noticed that using the Vulcan over the other two weapons seems to retard the rank's progression, as does using your options sparingly.
The wait-and-use options system can be unforgiving. It can get intense when you have to wait for the gauge to recharge which is done by not shooting. Sometimes I find myself dodging a bunch of bullets waiting for it to fill up, only to use a bomb to bail me out instead. BUT, when you're sucessful in unleashing an option at the most important time (esp. a rocket option) it is worth it, no doubt and extremely satisfying at that.
conclusion:
the game is badass
there isn't a such thing of a perfect game, even with the flaws, the game does so well in other areas that you're willing to adapt to get better.
it's addictive and blowing up stuff seems to be the theme covered so well in this game
doesn't hurt that this is probably the best looking DC game I've ever seen (yep, I said it)
if this is the last DC game, then it really did go out with a bang (pun intended)