my experience playing Kiliing floor, Counter Strike and Team fortress 2 is that KDE is a lot smoother than cinnamon.
I get stutter on cinnamon but if i log out and into KDE i do not. Tried usual settings but its still there. The desktop is nice and quick on cinnamon but something is up with frames / vsync even when altering settings where as its butter smooth on KDE.
if you stand infront of an edge on a 3d game using cinnamon and look up and down its as if a frame or two are shifted a pixel to the left so things look even more disjointed.
so far xfce and kde are the best mint distro's for gaming