'Reboot' doesn't have to be a dirty word. Shadow Warrior is a proper old-school FPS, a riotous full-fat romp with huge guns and hordes of enemies to point them at. Not to mention a katana and one of the best first-person melee combat systems we've ever seen. It's a must-play for fans of classic shooting, and Steam have a nice low price for it.
Not to mention a free demo, which you should try if you're on the fence.