what a game need:
- a good ai: you should not see any stupid npc
- story in game: If I must read the hole story on loading screens or on a doc that comes with the game, I will not play something like this
- do something never has been done!! Nobody want to see a slender game anymore, or another zombie survival shooter, which is not scrary.
- surprise the player

- graphic: can not be done in current FPSC without a lot of work and workarounds
- teamwork: I do not mean allies, I mean a person who gives you some hints. Everbody see the game with other eyes. everybody want something different and so you must find a good point in the middle.
I hope this helps you. I develope a game myself at the moment, so I also play a lot of games and look what is possible in fpsc.(Alternate Corno)
Corno_1