Scoring from the way I understand it is simply every shot is 100 points. Whether its an octo shot or not or even on beat its still 100 points. However, if you release the octoshot on beat you get a multiplyer all the way up to x8.
The best way to always be on beat, in my opinion, is to tap your foot or bob your head to the beat. You can't release on the offbeat only the downbeat.
Being a huge fan of shumps, rez, rail shooters, and having played the drums for years this game is a godsend.
Also, while I love the game.. passion is out of this world and makes me want a new panzer dragoon so bad.
The only complaint I have with it is the real life chick, I dont know why but it would be cool if it was just a girls outline like in rez.
The challenge mode however reminds me a lot more of rez's backgrounds and music.