personally i would like to see the game start off small like a rural town then get bigger like a city or country region, and then finally on a High-Tech Research facility island base. Staring most of the cast including back/over looked characters to give it that "ending the series" feeling, also wraping up any plot holes etc. I know it could become to complex in some areas but in my view the series needs an ending as a such, however make a new collection of games that use new characters, locations and viruses set in the same in-game universe. i know people will hate me for saying that but its my view and i know many will disagree with me.