#5
This is the strangest game on the list and I mean that as a compliment. You play chess, but when two pieces meet on the same square, the game switches to a first-person shooter duel to decide who takes the square. If you know chess, your openings matter. If you are better at FPS mechanics, you can muscle through positions you should have lost. My first reaction was that it would be a gimmick with twenty minutes of life in it. I was wrong. The mind games start before the duels do, and the combination of slow strategic pressure with sudden reflex moments keeps sessions genuinely tense. It is built entirely around one-versus-one, which makes it one of the purest two-player fits on this list.