( Had to cut my post)
Halo Wars :
Yup, I will play it this summer. 
Halo 3 : ODST :
Firefight : I will start with that, beacause that was the real addition.
Well, the biggest mistake was the fact that we couldn’t start matchmaking games, and back in time, I couldn’t play so much with friends.
Beside that, maps were great (even if we already saw them in the campaign) and fighting waves of cool ennemies, well that was fun. But I do think that, now, we shouldn’t have some sort of firefight sequence in campaign. For example, I found the end of the level The Package way too long, and that lasted actually in only one location. Except when the firefight is different, like in the space combat sequence… But we’ll get to it later.
Campaign : it was a short campaign, and the environnments weren’t really varied. I thought that it was mainly this modern streets.
But the game, during the night, felt really open, and It gave something new to Halo. Walking in the city, alone, by night felt new and refreshing. Even if that’s not what I really except from a halo game, this was still nice, but I personnally don’t want to play that again.
Again, great musics, alternating between epic ones and sad ones.
Halo : Reach :
Multiplayer : my biggest disappointment are the maps, first of all. Only grey, grey, and grey, and remakes that don’t fit with the new gameplay. Real maps should not be in the campaign. It needs to be distinct (you may tell me one disc is not enough, but I hate to play on places that I’ve already seen in campaign. Same goes for firefight, as I said.).
Forge is great, but the maps on the disc should have been mainly “real” maps. Forged maps should come later, with the community.
Then, AA. Well, I don’t think it fits in Halo. Sure, I love the jetpack and the sprint, even evade… But it’s truly impossible to make them balanced. And so, it ruins gameplay (Armor Lock, I’m looking at you.).
We have a bunch of new weapons to play with, and they are great, overall.
New Vehicles (I know that’s not just in multiplayer, but anyway…) are nice (falcon, revenant, sabre…) but the usual warthog is not really cool to drive in reach. It has weird physics.
And the Big team Battle, which I loved in halo 3, feels wrong, now. It’s either a pain to drive vehicles or a pain to be the infrantry, depending on the map I play.
About maps, pursue the work that was done by CA and you for the defiant Pack, because I love it. Won’t talk about bloom, because I’m not so disturb about it.
Though invasion was a great idae for a Halo, it really felt boring (2 maps, …), but that may not be the gametype itself that provoke it.
Campaign : the most varied campaign, yes. But I expected better than what we got.
I wanted huge environnments (well, okay, New Alexandria is huge, and gives new feelings, and is great, but i’m talking about epic stuff, and not that king of epic) with huge fights, not a cutscene that shows a great battle but then we are lead into a small section where we begin the level (Tip of the Spear).
Space Combat was outstanding, and this needs to come back for the next Halo. Maybe make it a little longer, or make a sequence that lets you go forward, through different locations (asteroids, etc.), and not just playing in one location, then cutscene, and then one new location.
The post-credit scene was a nice touch, but it can’t be done a second time in a new Halo.
I was also disappointed by the story, and the characters. I don’t know how to explain it in english, but I loved the story and the characters of Halo 2, so that may help to understand.
Firefight : matchmaking : great. Customisable settings : great.
I only have one reproach : like the multiplayer maps, I would like firefight maps to be really distinct (Unearthed). But I do get why it can’t be done (again, space on the disc).
Forge : well, this forge 2.0 is awesome, but the Forge World geometry doesn’t feel great to build on.
And of course, there is a lack of variety with the pieces, it’s mainly grey, grey, and grey again…
Besides that, I discover new gametypes every week, thanks to this, so it’s nice anyway.
Armory, theatre, sharing system… Good work, needs to be pushed deeper, though.
For me, the next Halo game should have that :
- an epic campaign, playable online, with a variety in terms of both gameplay and locations, with a big focus on story.
Try to create sequences like the scarab sequence that was cut for Reach, and make new ennemies, we need it now.
- a great multiplayer (matchmaking and customs), customisable, totally separated from the campaign and the firefight, with different maps that fit with different gamemodes.
- a great firefight, customisable (more than what we can change in Reach ==> vehicles, etc…) , totally separated from the campaign and the multiplayer, with different maps.
- a Forge that isn’t redundant.
- Side stuff like Theatre mode, armory, nice menu, etc…
Well, I ask a lot.
But if Bungie didn’t spend months trying to create the hovercraft, which was cut in the end for real reasons, they could have created other nice stuff… You get what I mean, I think.
I have faith in you, 343i. 