: It looks like they just hacked some Halo 2-ish gameplay into Halo 4. The
: graphics look like straight Halo 4 engine, the scenery looks like Halo
: 4-style scenery, the elites look like Halo 4 elites, the first-person
: character model including the knees like like a Halo 4 first-person view,
: the text that pops up in the middle of the screen is pure Halo 4-esque, etc.

This might have been talked about elsewhere now, but they've said now that the six remade Halo 2 maps run on their own engine, so that's what's going on with this.