Last night I fired up Robot Tank and have to say that I think this cartridge kicks Battlezone's ass.
What I always hated about Battlezone is you had to wait until your shot hits something before you could get another shot off. And that downright sucks if you miss because you're going to be toast from the return fire. For this reason alone makes Robot Tank a better game.
Sure Battlezone has different enemies, but Robot Tank gives you fog, nighttime, locusts and raining frogs...