[geodav]

yes one man can make it but you have to be very realistic about what you want and how long it will take, a few blown game will take a team 2-3 years full time to make, on your own that would mean every evening for 10-15 years, you best bet is to start small 1 character + 1 weapon + 1 level. as for which 3d app to use that depends on which game engine you use as not all 3d app export to all games.

not much help i know but if you look about the modding scene you'll find most mods take 2-3 years to reach a final release if at all