There's not many games on the Xbox 360 where you get to shoot dinosaurs, including games that throw a little bit of Halo along with it. Orion: Prelude does just that and features multiplayer too...
Ok, so it is not really Halo, it just looks a lot like it. Dinosaur games on the Xbox 360 also have a history of being easy points - eg King Kong, Jurassic The Hunted, et cetera - so it is a real shame that this game is also only for Xbox Live Arcade and not a full retail disc. Even more of a shame is that there's no zombies either.