Halo games are stuffty. Just decade old unreal tournament, with newer graphics.
That's probably why they're beloved, especially the multiplayer. They're relatively simple; Shoot and kill. Just about anyone can pick it up and have fun with some friends. I'm not saying Halo is GREATUST GAME EVAR but it's by no means a bad game. It's not advanced nor the pinnacle of modern FPS games though, either.
Not even traditional bunnyhopping?
Jumping slows you down.