Halo wasn't revolutionary, it was a decent fps with spacetheme...
Though castlevania, doom , final fantasy, and yeah , when the sims first was released it was revolutionary, even if you like it or not maxis released one of the most popoular games ever made wich opened a whole new simulation genre.
But Halo is revolutionary. It brought about all of this regenerating health, didn't it?
Or I could have the wrong definition of revolutionary.