This has to be one of the more innovative games I've ever played. It's not flashy, it doesn't have great physics or single player AI (AI is dreadful and extremely unintelligent) but the feel of it is incredible. Instead of the regular "running rampant around a map and shooting on sight" style of gameplay, everything about The Ship is sneaky. You can't just openly pull out a weapon or you will be jailed by The Ship's (conviently placed) police. Instead you have to stalk your prey and trap them, pulling out a fire axe, flare gun, butter knife or other weapon, when the time is right. My favourite technique (on the map Batavier) hiding behind closed doors and axing n00bs as they come through. Watch out ;).