You can let the computer be Player One, Player Two or both players. There are three difficulty levels: Beginner, Average and Expert.
If you choose Beginner, the computer doesn't care about the opponent and just moves around. This is the same algorithm as used by xtron-1.1.
At skill levels Average and Expert, the computer tries to hinder the opponent when he comes near.
See the Menu section for information on how to configure the computer player.