So I've played some 15 games or so (my rank is gold 3 or something, no idea what that means). Overall, impressions are cautiously optimistic. Honestly, it really does feel a good bit like Halo, but with some neat and not-so-neat stuff added.
Good:
+guns look, sound and feel strong. Except for the sniper, which is basically identical to H4's
+back to traditional slayer focus of "know when power weapons spawn, grab them and control the map" rather than random drops
+no grenade indicators!
+60fps
+thrusters
+good map callout names
+spartan chatter
+sprinting comes at the expense of shield recharge
Bad:
-map visual design. both maps are super busy, especially the midship one. It's got this weird hazy thing going on that really obscures vision
-ADS/hovering/clambering/groundpound/spartan tackle thing. They're all totally unnecessary. Can't stand ADS at all, especially as it's not just cosmetic. Hovering is just kind of there and feels unnecessary. Clamber is way too forgiving, and pretty much kills trick jumping. Groundpound is useless 85% of the time, no reason for it to even exist other than that it looks cool. Definitely not gonna be a fan of it in KoTH matches. Spartan tackle is just 1hk melee, and isn't very fun.
-Steitzer callouts. Same problem as Halo 4 - he's way too enthusiastic, haha. Maybe I'll get used to it.
-Automatics are stupid strong. AR and SMG scoped in wreck everything.
-The DMR feels useless every time I use it. Probably because the maps are pretty small.
-Weak audio with grenades. Hard to pinpoint where they're landing even with my 7.1 headphones on.
-Killcams. Especially that music.
-Prophet's Bane glow just eats up my screen. Looks really bad
-Ranks need more prominence and explanation.
-Sword ADS. like seriously why does that even exist
-The human map is kind of bad.
-Heads up notices on power weapons. Let people figure it out for themselves when snipe spawns, that's part of the learning curve.
Even if this ends up terrible, H5 so far is better than anything in H4. I'll give 343 credit for that. I've had some real fun tonight.