In addition to open, checkpoint free, non-liner sandbox levels...
1. David Bateson (47), Jesper Kyd (Music\Soundtrack), and Vivienne McKee (Diana) return to the series.
2. Old Disguise system, not one where you need to tab instinct every 2 seconds to stay undetected.
3. An actual good, non cheesy story. Or at least one that isn't obtrusive and dictates level design like in Absolution. And villains who are actual threats, not idiots out of a comic book.
4. Point system replaced with the old money system, and the ability to purchase new customizable weapons and other useful items with that money. And don't have the money\point counter on your screen during gameplay, show it at the end of the mission.
5. The ability to close doors, drop items, look through keyholes, etc.
6. Professional environments and AI. Not overly obnoxious like some levels and AI were in Absolution. It's fine for an easter egg here and there, but the levels and dialogue was overdone and made the game feel more like a comedic one instead of a serious one.
7. Return of the live aerial map instead of instinct.
8. Non-trashy environments. It seemed like every single level in Absolution was run down\trashed, with garbage all over the floors and decaying buildings.
9. Actual melee combat instead of button mashing.
10. Remove the annoying sounds\animations from the "detection arrows" and the shhhhh...BING that happened if you were detected. A simple detection meter like in the previous games would work fine without the annoying and distracting system of Absolution.
There's a bullet for everyone.. And a time.. And a place..