I've been playing Halo 5 for almost 2 weeks now. For anyone interested, here are my early impressions (spoiler-free, of course)

It's really freaking good.

Some background: I love Halo CE - Reach, not crazy about Halo 4. I like a challenge, so I play almost exclusively on Heroic or Legendary. I play an even mix of Campaign and Multiplayer. I don't really have a favorite Halo game; there are aspects of each that stand out to me. But if I had to pick one, I think Reach offered the best "total package".

So about Halo 5:

I think the campaign is excellent. The squad dynamic is a nice twist on the usual Halo combat loop. It feels new and different, but it fits perfectly into the sandbox. You feel like a wave moving across the battlefield, crashing into anything that stands in your way. The new movement abilities play into that perfectly, as you climb, sprint, and leap all over the place.

In terms of difficulty, Heroic feels like the sweet spot to me. It's challenging, but it feels well balanced. Legendary is fun from a "I want the ultimate challenge" point of view, but it's so punishing that you end up spending most of your time cowering behind cover and looking for safe corners where the enemies won't follow. It also reduces your AI companions to "useless" status. It's doable, but you don't feel much like a Spartan on Legendary (side note: this is one of the things I love about Reach... they hit a perfect sweet spot with the legendary difficulty. It's incredibly challenging, but doesn't reduce you to cowering the entire time).

As far as the story goes, Halo 5 might be my favorite in the franchise. The plot itself is nothing groundbreaking, but I found some of the little character moments to be a lot more subtle and interesting than what we usually get in a Halo game. They also avoid hitting us with a big info-dump or 20-minute cutscenes purely for exposition. Instead, the leverage the fact that you always have AI characters around you and reveal a lot of the context and backstory through dialogue as you make your way through the missions.

It's worth mentioning that the whole "Hunt the Truth" campaign is hugely misleading. I won't say what this game is *actually* about, but it certainly isn't Locke vs Chief. There's a tiny bit of that in there, but not much. I only bring this up in the spirit of expectations. It didn't bother me as I was playing the game, but if anyone goes in hoping for the ultimate Spartan vs Spartan showdown, I think they'll be disappointed.

As far as multiplayer goes, I haven't played enough to say much. I think the new abilities all fit nicely into the PvP sandbox. Warzone (the 12 v 12 mode with AI foes and capture points) is a lot of fun. Hectic, but in a good way. Plenty of options when it comes to deciding how to approach the battle. Lots of room for coordinated teamwork and strategy.

The arena mode, I'm not sure about. Arena is the 4v4 mode, and includes plenty of classic Halo gametypes. I think that Halo 5 excels on the large scale: when there's loads of infantry and vehicles and AI bosses all scrambling around each other, it feels awesome. But the intimacy and simplicity of the 4v4 modes highlight a few weaknesses; Halo 5 looks and feels great, but not as good as a certain other FPS that many of us here enjoy. I was never able to play more than 2 or 3 games before switching back to Destiny just because it feels that much better. Still, I think there's a lot to love about Halo 5 multiplayer, and I look forward to seeing how it is after launch when we have more playlists to dive in to.

TL;DR - Campaign is excellent, multiplayer can be great, but I'm not 100% sold on it yet. Overall a huge step up from Halo 4.