SSF2 is the game ala SSB, but made entirely in Flash from scratch.
It’s pretty fun. 
It has online mode, training mode, events, solo, normal battles (free-for-all), team battle and more.
If you want to battle me, my name is Sanic_the_fast.
I main Sonic, and I’m an easy target. 
P.S. You can get it for free on the mcleodgaming.com!