No, Alpha Prime does not have any multiplayer. This is as a matter of fact, a good thing. There are plenty of games that are devoted to multiplayer, UT2004, PlanetSide, Counter-Strike Source, Quake III just to name a few. Games such as Quake IV, Doom III, Prey or Painkiller - although SP-oriented, do support multiplayer, but are nowhere as popular, as MP-dedicated games. So, when you create a game, it's a good idea to focus on either SP or MP, not include both - concentrating on one particular "layer" of the game makes it real good at the point.
Alpha Prime is a GOOD single-player shooter and let it remain that way