Not bad, but certainly not amazing.
Graphics: 9
Okay, Ikaruga has some great visuals, excellent camera angles and a crisp (although 50hz) framerate. I also liked the inclusion of a flip mode, however they could have added a screen strech option for the normal topdown view much like raiden dx on psx had.
Audio: 7
Nice sound effects, but the music doesn't make me want to catch a plane to japan and buy the OST. If you want a shooter with a decent soundtrack, you're gonna have to try something like U.N. Squadron or Strikers 1945.
Gameplay: 5
Here's where the game takes a nosedive. It's nice the first time through, but you're not gonna see much change playingg it over and over. Only the hardcore shooter fan is going to get enjoyment out of racking up the highest score possible. However, the way you unlock more credits is an okay idea, It adds a bit of added playtime for players with average skills, but if you're a hardcore player, one time through with the default credits is all you'll need. One thing I really DID NOT LIKE was the fact that there is no powerups at all, I mean come on, what is a shooter without 500 weapons and powerup icons, it kills half the game, really.
Replay Value: 3 (5 if you love your shooters)
I really didn't find this game drawing me back for a 432nd serving, maybe only a 3rd. But if shooters are your thing, you'll see yourself coming back a lot, if you like shooters with no powerups WHAT SO EVER, that is.
Overall: 6
Not bad, but certainly not amazing. This could have been something a lot better, shame on you, Treasure. Capcom and Psikyo are still the champions of the shoot 'em up genre in my book, Treasure still have a lot to learn when it comes to gameplay and replay values.