I find Vanguard Princess much more fun to play than Street Fighter and I think its because of all the cute moesome characters in it - but not only that, its very playable and entertaining too!
Is available for download from Vector - click the blue button. And its free!
I ran it on Parallels and it worked completely fine - I just need to dig out my PS3 controller to USB attachment. You can still play using the keyboard though.
Check out the sample game play videos below. I only watched for a few seconds before I downloaded ^^;
You can see the control methods here and introductions of each character at Seizon kakunin.