I realise that by now, this thread has become far too large for my comment to be read by pretty much anyone, but still, this is what made the first game innovative and the sequels equally supurb examples of the genre:
Vehicles: Halo was the first game to seamlessly switch from free range roaming on foot to free range roaming in a vehicle. The vehicle controls remain some of the best in an FPS game, where most games tend to give vehicles a backseat.
Weapons: Halo was the first game (or near as might as been) to limit you to only two weapons at a time. Combining this with the remarkably wide range of inventive, carefully balanced weapons, each with its own feel, made weapon choice part of the strategy.
Regenerating Health: Well, I know that technically it's shields (making it more realistic than the games that mimiced it) but merely the fact you had recharging health made a world of difference to the game. This is where the true innovation comes in, because can you think of an FPS before Halo that had recharging health, or a game after it that didn't?
Storyline: Although the first course was a little small (although certainly confidently executed), the second and third games delivered a depth of storyline that very few games, let alone FPSes, have equaled.
I can understand why people picking the game up from the third, or even second instalment might say that it's just more of the same, but if you played it when it was first released you would know that is because the genre became the same as the game.
It's my opinion that anyone who says Halo is actually a bad game is just being contrary.
