A finer gaming experience has never been crafted
Halo is for FPS fans, first and foremost. If gunning down aliens brings you no joy in life, please, begone. This is not the review for you. I know -- repetitive game design. I know, it wasn't that fun. Well, it's still a marvellous game insomuch as it creates and sustains atmosphere and tension. I seriously wanted to know how the story unfolded, something I can say about very few games. Diablo II is perhaps the only other game that springs to mind.
I could go on about the innovative weapon system -- two at a time -- but you know about that. Then there's the regenerative shielding! So much better than the standard DOOM scheme. But we all know all about these things.
One feature that often goes without notice but which is central to the effectiveness of Halo, is sophisticated enemy AI. In short, enemies have emotions. If they see you cut a swath through their comrades they will turn and flee, screaming their heads off in the process. Should we really take this for granted? Well, to disrespect Halo is certainly to do so. But I think it's one of the greatest things ever put into video games: enemies that know when they are being crushed and who respond accordingly.
Another beautiful thing about Halo is the mythic grandeur of the Forerunner installation. Exploring vast reaches of this ringworld, both inside and outdoors, imbues the game with a largeness of scale and level of intrigue unheard of in comparable games. If you buy into the mythos surrounding Halo, you really feel like you're on a grand structure orbiting light years from Earth, and that you ought to redouble your efforts to smack down the Covenant and Flood malefactors in your way.
Halo is perfect as far as I'm concerned. If I had played it on the Xbox rather than the PC I'm sure I would have thought it a little more middling. But with your finely-tuned mouse you can pop off a few heads and feel great doing it.
If there's one thing I would have been really happy with, it would have been a cooler population of people playing online, after I'd gotten tired of the single player campaign. Unfortunately, back in 2003 (and perhaps still today), 95% of players are just idiots intent on killing killing killing, never getting into a fun game. Oh well, what can ya do.
The Bottom Line
Majestic, atmospheric, and grand. Halo kicks the hell out of most other FPSes, and certainly its peers from the 2002-2005 period.