Are the robots we create alive?
In positive entropy, organized phenomena becomes more disorganized. It is the natural course of the universe.
In negative entropy, disorganized phenomena becomes more organized. The catch here is that a system needs energy to reverse the natural course and have negative entropy.
No robot in Robocode consumes energy on its own, unless a user plugs the computer in a wall socket. If a computer/robot knew how to find energy on its own and plug itself into an energy source, then we would have some form negative entropy. If they knew how to repair themselves and/or replicate themselves and their existence would prevail as long as there is an energy source, then the negative entropy definition of life would be completely fulfilled.
You're implying that something has to have a physical presence to be considered alive. Whether something is physical or virtual doesn't affect its state of order.
The robots, in a way, do repair themselves by hitting the opponent and getting the energy bonus. It is impossible for them to "reproduce" in the sense of creating new robots in the middle of a battle. Their existence prevails as long as they kill the enemy and avoid getting killed themselves.
To fulfill negative entropy, yes it needs physical presence. Binary states changing back and forth inside a computer don't relate to entropy and are thus irrelevant to this definition.
Virtual robots in Robocode exhibit intelligence which is a 3rd concept. But intelligence as a combination of perception and decision making. Intelligence can help a system achieve negative entropy. Although most Robocode AIs are designed to maximize destruction. If they were ported to a physical robot, they would be maximizing positive entropy.