I remember finding the rules to this game on the internet, oh, 15 years ago or so. The players (typically (or necessarily?) two) sit around a table. At every "turn" - for advanced play indicated by some clock or so, but for beginners like me when all players agree that they have worked out what to do next - each player simultaneously reveals two hand signs out of an alphabet of five or so, independently with the left and right hand. Hand signs were things like a wavy line, pointing with your index finger, or a fist. Then there was a dictionary of ten or so sequences of three to five hand signs that form spells; you look for each hand if the last couple of signs match any of the spells exactly, and if they do then that spell takes effect - for example, if "fist - wavy line - fist - point" would be "lightning bolt" according to the dictionary, then if for the last five turns your left hand had done "wavy line - fist - wavy line - fist - point", that would trigger a lightning bolt. I believe players started with a certain number of life points; there were damage spells, healing spells, counter spells, maybe a shield spell as well?
The fun of the game was, of course, that you'd have to figure out what your opponent was building up to with both her hands, and evaluate if you could afford to carry out your own plans or whether you needed to do something to counter it. Also, sometimes you could come up with nice combinations: the last few hand signs of one spell might form the first few of another, so you could make them overlap for higher efficiency.
I'm pretty sure this was never a commercially published game - since there are no physical objects to sell, that would be a tricky proposition anyway.
Ideally of course I'd like to find the game rules as they were available back then, but I'd be happy to just hear from people who remember this as well. I would even be open to trying to recreate it collaboratively, if anyone is up for that sort of thing.