I've owned this game for quite some time but always had forgotten to check out the Xbox live features. No one seems to play it though. I'm curious why. Perhaps it isn't that great?

Just play single player of the game.

I'd be interested! Send a friend request. Any one else?

I still play it from time to time, feel free to send a friend request.

Any achievements for online mode?

No achievements, but it is pretty fun. If you're up to testing your favorite characters strength, then this is for you.

Did you beat all charcter story mode in the main game?

I have not beat all of the character story modes yet. But  I am still working on it :D

Should I start everyone in free mode first and max them up?