The suggestion with the flasing outline and that the CPU-player could give a signal to the human-player, when he's ready for handing over some orbs, is not bad. Maybe it could also make sense, that also the human-player could give such a signal to the CPU-player (for example by pressing the SPACE-Bar), when he wants to hand over orbs vice-versa?
But i am not a programmer and i don't know, how much playing-intelligence could be realized for a CPU-player on a 8bit machine like the C64, when it comes to things like cooperation and reacting on the moves of the human-player?
I am sure, it would not be a big problem, to let a CPU-player play his own game alone in a very high strength here in this puzzler-game, but when it comes to cooperation with the human-player to pursue a common aim, then i am not sure, what's technically possible and what not on 8bit machines? An interesting thing, these cooperation thoughts with a CPU-player, are anyway, because such things are not so often to find in C64 games.