Warning, this is opinion and I am not trying to prove anyone wrong or change people's opinion for the most part. XD
This will also be more discussing First-Person Shooters, and not just Shooters in general.
I kept it somewhat short, and didn't want to go on a long wall-of-text.
1. Larger-scale Sci-Fi
2. Voiced Main-Characters
3. Cutscenes
4. Optional expanded universe
5. Freedom of Creativity
6. Lots of story in games ignored
7. The villains aren't Russians.
8. The Music.
9. And lastly, Gameplay.
Well this is the end of this, feel free to discuss it, agree or disagree on the statements. Be CIVIL, when discussing, please make sure you know about at least what you're discussing so it doesn't become a one-sided flame-war. In that case, no flame-wars please!
This will also be more discussing First-Person Shooters, and not just Shooters in general.
I kept it somewhat short, and didn't want to go on a long wall-of-text.
1. Larger-scale Sci-Fi
Most of the shooters I have played that are Sci-Fi, they seem to always be on worlds in cities or such and never going into space. What I love is how in Halo you fight your battle on various places, Earth, The Rings/Ark, on Space Stations, and they all give lots of variety. It gives the sense of a large-scale world that this isn't just events in small areas.
2. Voiced Main-Characters
Master Chief (halo 1 -3) doesn't talk too much but for me, even just the little dialogue is good. I have a problem with mute protagonist. It takes me out of the game and especially when other characters are chatting up a storm. When they talk but not the character I am doesn't, it makes me feel like I am not there. While it is harder to input yourself into a character who already is established, it at least makes me feel like I am a person in this universe and that my actions have at least weight to them.
3. Cutscenes
I love cutscenes, seeing the characters move about with better angles and such really sets the mood. Being able to move around and do anything doesn't help set the mood at all, sure you could stand there, but like I said above in 2, it doesn't make me feel like I am there because of the fact that I can do such things.
4. Optional expanded universe
What I feel is much unappreciated of the Halo universe is its expanded universe. It delves into area's games can't go into (since gameplay is obviously a huge factor in the games) and allows people who like the universe to see much more. What I hate is sometimes where you get this awesome universe in a game, but after you beat the game. That's it, you can only repeat the story, you can't experience other sections of that universe.
5. Freedom of Creativity
Going side-and-side with 4, Halo has an expansive universe with so much to it. People fear that Halo 4 will be exactly like previous games and be a simple cash-in, but I feel it won't. There is much more to Halo then just the Human-Covenant War, there are still many mysteries left untapped, and galaxies left unexplored. Halo 4 may fallow Master Chief, but just because he is the vessel that we experience the games, doesn't mean that ends all creativity. What the MC experiences, sees, and interacts with has endless possibilities.
6. Lots of story in games ignored
In the games, cutscenes provide most of the story and shows much more than people give it credit for. Recently I re-watched Halo 2's cutscenes and if I had just watched that, I would have still gotten a lot of lore and such of the Halo universe (which helped by the fact that it showed the covenant side of things. But also, there are stories that aren't in cutscenes. Starting in Halo 3 and on forth, there were the terminals which provided lots and lots of insight into past events and background of the universe. Halo 1 and 2 didn't have these, but in Halo: Anniversary, there will be. In Halo 3: ODST, and Reach they were Data pad which expanded on the UNSC and Earth's history.
7. The villains aren't Russians.
More of a tagline, but many shooters now feature Russians as the villains, as more Modern Shooters have taken over. Despite there being 6 Halo games out currently, I still find it more fun and such to fight the Covenant then any Russians. Plus it's plain annoying now. But there isn't just the covenant, but also the flood, and if Halo 4's Ancient Evil is to believed, a whole new race of aliens.
8. The Music.
Honestly this is probably one of the series greatest aspects. Martian O'Donnell does a tremendous job on the soundtrack. All of them fit the levels and help the game's atmosphere settle in.
9. And lastly, Gameplay.
Halo gameplay's is a mixture of Old-School and New-School, it doesn't have iron-sights, you rush more in the games then just moving forward, hide, shoot, and rinse and repeat. You can jump much higher than most modern-shooters giving the game more sense that you're a Super-Soldier and not just another Marine. But also keeps New-School with 2 weapon wheels and things such as that, but even then, the weapons themselves are fun to use, all have their weaknesses and advantages but also don't feel the same.
Well this is the end of this, feel free to discuss it, agree or disagree on the statements. Be CIVIL, when discussing, please make sure you know about at least what you're discussing so it doesn't become a one-sided flame-war. In that case, no flame-wars please!