2. Support. How much time will you support Crysis 3 with patches, fixes, and such? Crysis 2 support was something like 4 months IIRC. No game can be played without support from developers.
3. ANTICHEAT, I stopped playing Crysis 2 exclusively for this (people running firing infinite ammo doing headshots)
4. A good end game Boss like Crysis 1. Crysis 1 was EPIC, I can still remember many parts of that game but none from Crysis 2. Crysis 2 was like: "mmm was that a boss???"
5. Configuration options
6. You should take some things from Blacklight Retribution, they have done a good fps (a bit overwhelming with too much customization)
I think I'm done