-More cut scenes. There aren't a whole lot of them right now, but the ones that do exist are shot so damn well. Just get some better writing to go along with them (at least House of Wolves level of writing) and half of the game will feel like a good movie. Oh, and make them skippable, too. -More dialogue during missions. Borderlands does this a lot, and I personally think it's a great way to tell a story while not interrupting gameplay. Thankfully, Bungie seems to have realized this and put a bunch of dialogue into the House of Wolves missions. -Less bosses that are just bullet sponges. Give them unique mechanics, like the raid/PoE bosses. At the very least, make them fight differently than the normal enemies. -Put the grimore stories into the game. The grimore has some of the most interesting lore I've ever read in a video game, and that's coming from someone who's played Dark Souls. It just frustrates me so much that almost none of it is in the game. At the moment, that's all I can think of. Didn't mention additional planets/more exploration because I figured that was a given.