| Ikaruga
I'm a big 2D shooter fan, and have had Ikaruga since it came out on the Dreamcast last year.
Stu - it is amazing, but two things:
You really should rotate your TV/monitor if you're serious about getting the full Iky experience. Those crappy black borders just make it look weedy. Don't be scared to do it - just make sure you leave your TV unplugged ( from the wall ) for at least ten minutes, turn it, plug it back in, then away you go . . . repeat the ten minutes when you wanna turn it back . . .
. . . which is the other thing - Ikaruga is incredibly frustrating. It's amazingly clever, but so unforgiving. I found it hard to enjoy formore than about an hour at a time. It's well worth the investment, and 2player is a total blast, but make sure you've got another game on the back-burner to take a break with, because Ikaruga will drive you insane.
It's also well short, if you've played Treasure's other games, you should be used to their length (quality not quantity), but even by their standards, it's pretty brief. It does have loads of replay value though.
Anyway, hope you like it - just wanted to give you some info so you're not disappointed like half my friends who bought the DC version were. | 
