I recently tried the demo of Portal on XBLA, and was really impressed by this offbeat game. I went ahead and purchased it (1200 points -- the only downside!), and have had a blast playing it. This is unlike any other FPS I've played, because the focus is all on the puzzle-solving aspect. A few maps have timing/agility aspects as well, but generally it's all about playing smart and staying alive.

The game did feel a bit short, but it was still very satisfying. The challenge maps, which are stand-alone maps not part of the main game, are a nice bonus for replayability because you are trying to achieve certain scores on each challenge map, like fewest footsteps, lowest time, fewest portals, and so on. There are also some cool easter eggs / achievements sprinkled throughout the game.

I think Pat would really appreciate the deadpan humor of this game, but I suspect all the bubbas would enjoy it. Try the demo out for yourself!