Here are my thoughts.
1. The lack of indicators above your teammates' heads is a terrible misstep. It's ridiculous that I'm constantly trying to figure out where everyone is. I know there are twelve people and it may clutter the screen, but honestly with the way it is now, it's frustrating.
2. Radar is atrocious. the radar in Halo 5 has to be the worst in the series (and I don't say that lightly). You can hardly tell when someone is nearby unless they're right up on you. This is especially bad in Arena, but it's also a little annoying in Warzone.
3. The AI bosses are worth too much and can be stolen too easily. Okay, let's really look at this for a moment. You can have all three bases, kill dozens of enemies, but the other team goes after a boss that happens to spawn near their base and suddenly they're winning. It would be one thing if the boss was worth 25 points, but no, he's worth 150! Are you serious? Killing that one boss is worth 150 points, the equivalent of 150 Spartan kills. Ridiculous. What's even more absurd is that you and your team can be killing one of these bosses, take down their health by 98%, and then the enemy comes in at the last second and steals the kill. Maybe they use a rocket or a sniper from far away. Maybe they just sneak in. Either way, it's completely unfair. An easy solution for this would be to split the points based on how much damage your team has done? Either way, it is extremely unbalanced right now and turns the game into a "who can kill the most bosses" fight.
4. Taking bases isn't worth it. Thanks to #3, the entire objective of the game is made null. You can take all three bases, but they don't get you any points. You can get some REQ points, sure, but there's no score increase. The entire game seems to be focused around boss kills. Nothing else even comes close. There needs to be a score increase for taking them or at the very least you should accrue points while you're holding them. As it stands, they absolutely serve no purpose except to delay the enemy from getting to your core, which ultimately rarely happens because almost every game is decided by boss fights.
5. This is just a personal issue I have, but I really dislike the fact that REQ packs take so long to get. I mean, I understand that 343i/Microsoft wanted to leech as much money out of people as possible by adding microtransactions, but this is just ridiculous. It takes about 5-6 games of Warzone to get a gold pack. You open it and you have no idea what you're getting, and sometimes it's just worthless. I haven't gotten a single tank and I've opened about 8 Gold packs now.
1. No Big Team. No information on when Big Team is coming. This should have been in the game at launch. No Halo game has ever released without this gametype. 343 says they wanted people to focus on Warzone at launch, but come on. Dominion launched alongside big team in Halo 4 and people still played both. There's no reason to think that players wouldn't be trying out Warzone. The reason for this delay seem, to me at least, to be because they wanted us to buy the microtransactions. That's really the only reason I can see.
2. Lack of gametypes. There's no Capture the Flag. No oddball. No VIP. Nothing. WTF? Are these even getting added in? Where did they go? The Arena gametypes seem pretty barebones with only CTF to quench the traditional Halo thirst. Halo has always been defined by its unique gametypes like CTF, King of the Hill, and Oddball, so what happened?
3. The story direction was awful. Setting up a favorite character to be a villain just felt unnatural and made very little sense, given that character's past. It almost feels contradictory. We also barely had any time with Blue Team, which was a real shame because I found their missions to be the most fun. Locke was uninteresting and felt very two dimensional. Buck was the best character on that team, so it's a shame they just didn't make him the lead. I would have loved to see that.
4. Some weapons are unbalanced. The pistol is OP in this game, which should never be the case. I know it was that way back in Halo 1, but it was a problem and was soon after resolved. I find that in Warzone, before I'm killed by a BR, most of my deaths (or others' deaths) are from pistols. Shouldn't the AR be on par or better than a simple handgun? I honestly think it's because of the new scope feature they've added (Smart Sight? I forget the name). Regardless, the pistol needs to be toned down significantly.
5. No campaign scoring? Why? What possible justification could there be to leave this out? There's also no campaign medals or a way to track your kills in co-op. I liked fighting my teammates for the most kills to see who died the least and killed the most. That's all gone now, which is a little baffling because this game is supposed to be multiplayer and co-op driven, so why leave out one of the biggest co-op features of the past several games?
This game feels very unfinished, not in the way it plays or feels, but in its features at launch. The campaign doesn't really conclude, either, and the ending just feels rushed. The ending for Halo 4 was much better and felt very natural, with a long cinematic that felt earned and resonated with most of us. Chief stood there on the ship, staring at Earth, reflecting in a long silence over the biggest loss in his life. We didn't get anything like that at the end of 5. There was no reflection, no real character development. It just ended. Halo 4 also felt like a self-contained chapter in an epic tale, not like Halo 5 where it feels like half of a plot. Then of course you have the missing features in multiplayer, including Big Team, King of the Hill, Oddball, and the lack of a scoring system in co-op campaign.
I don't know why all of these features weren't in the game, but I strongly suspect it had something to do with shifting the development focus to Warzone and its microtransactions, I suppose business is business, I guess, but I'm very disappointed with the direction they took with this game. If they add in all of these missing things, then great. I'll play the crap out of the MP once they do, but right now there's no word on it, so I'm left twiddling my thumbs. Come on, 343. At least tell us where King of the Hill and Oddball are. Let us know if you're adding them. That's all I want.