Run Half life (old) on iMac g3?

So, I've recently gotten my hands on an old imac g3 (500MHz, 192 MB ram, like, 30 gig hard drive or something, and its running OS X 10.3(panther)) i know i cant run a virtual PC because not enough ram, and the CrossOver Mac is out to, it needs like, 10.4 or higher i think, so i want to know, how can i get the old half life, not with a source engine, the one with the quake engine i think running on it? i don't care if it'll be a little slow, just any suggestions you guys can throw out would be great!