But Counterstrike has a very small map that looks a lot like Sup'Air in one of the maps you can get from counter-strike.net.
That said, there's a limit to how much you can pretend you are playing paintball when you've got an AK or an AWP in your hands and when you headshot someone they fall over with a distinct lack of skull.
You could always give Nerf Arena a try. That's great fun after a few pints and a bit of a smoke.