It looks fun just judging by this trailer.
That said, the "armor ability"-esque moves looked a bit worrying/possibly annoying depending on how they actually implement them within the game. Though I am optimistic with 343 and how they handle these things after Halo 5, even if H4 sucked in this kind of area.
Obviously sprint is still in and a core aspect of the game's identity. But the game looks a lot slower than Halo 5, which is either a good thing or bad thing depending on your opinion of it. Me personally, I think slowing Halo down from 5 might be a good idea on the whole and for most people/the game more generally, but I also think it's kind of a bit disappointing for me game pace-wise, just from looking at this trailer. I'm someone who actually quite liked the pace and movement options of H5 and how you really had to chain them all together and be fast to really be good at it. I liked thrusters, hovers, and ground pounds and all that stuff definitely looks to be out of the game.
The guns look good and fun, which is important.
Can't wait to actually get my hands on it for myself to see how I really feel, but I'm excited and hopeful.