As far as I know, there are no "cheats" to do this. However, if you are looking for a shorter gaming experiance, when you fight Seraph, loose. You will be unplugged from the Matrix and skip right to the second-to-last level (Tunnels of the Real). If you beat Seraph, you will be taken to the Oracle and you will have to do two or three more levels (not sub-levels, real long levels, mostly Agent Smith escapes.). If you are looking to skip a level you are having trouble on, I guess that is just too bad. If you are stuck, go the the Enter the Matrix Help Thread and post your problem and anyone who knows the answer to your gaming dilema will help you out! Hope I was of some assistance.
-DM31
It is official from the programmers of ETM.. Neo cannot be used. They said that this was done on purpose to show the importance of the main characters of the game. to be honest.. this game ended all crap like, and it baffles me why neo cannot be used in multi-player mode. Anywho this game disgusted me in its length. but the movies were not half bad. only bad thing i can say about those is how you have to turn up your TV to hear them talk in the movies and then turn it down before you resume game play. Very annoying and could have been programmed better.