A shame so few have played this game, because it is undoubtedly one of the best games on the original Xbox console.
Shining above all else is the game play itself, however. There is a blend of first person shooting, stealth, hand-to-hand combat, platforming (and even a bit of role-playing) unlike I've ever seen before. All of these are handled very well and flow seamlessly with each other. You can find yourself in a dark room with an enemy, slit his throat silently (or maybe get into a fun close-quarters brawl), take his gun, climb up onto a couple of crates in the shadows and start picking off his buddies.
My biggest complaint with this entire game is the lack of any multiplayer mode, which just seems obvious to me, and is pretty much needed in todays games. And any 360 owners will be forced to play it on Xbox (until Assault on Dark Athena comes out) for now, because it is not a backwards compatible title. It also can be considered a fairly short game, on the easier difficulties. Overall, however, it is one of my favorite games and I do not think anyone should miss out on the experience, especially if you are a Riddick fan.