It's hard to tell if the 60fps frame rate looks "natural" or not from the footage. Nintendo games like Mario Kart 8 and Super Mario 3D World run at 60fps, but don't have that unnaturally smooth look that many 60fps games have. I guess it depends on the overall image quality, art design, animations, and other factors that determine whether something looks good at 60fps.

Bloodline still looks way too brown and ugly (seriously, is green grass and blue skies too much to ask for?), but the layout changes look interesting. There was always a huge lack of cover in the middle of the map in previous incarnations of the Gulch.

The Grunt Birthday Party skull looks great, all sparkly and colorful.

It looks like they're reusing old Bungie-era assets for Grunts, Jackals, and various weapons in the H2A campaign, and even the ones that aren't direct copies look like reasonably faithful to Bungie-era Halo.