That's a very general question, Russell. Making a full game with Mugen bascially means gradually adding characters, stages, music, etc, until it's... a full game, I guess. Adding completely original content, such as original characters, will make it a truelly full game, if that's what you mean. But just making one decent character can easily take you a year or more, so it's quite unrealistic really. One of the few totally original Mugen games is;
http://www.theblackheart.com.arIf you just mean taking already exisiting characters, like Ryu edit number 764 and stuffing them into Mugen, well, you can do that in a couple of hours. If you're totally new to Mugen, check out the tutorials that are on this site.
