Joeand Mac Caveman Ninja is a Sega game that has been put into abandonware category, meaning it can be played without restrictions.
You're a creature somewhere on the path between simian and homo sapiens and you've just found out some of these loonies form another tribe have stolen your females! At first you scratch your head a bit but after a short while you grab your club and run over to the other tribes' cave an thump some Neanderthal heads.
This is not quite the way Joe and Mac, our Caveman Ninjas go about. First of all: these cavemen live in a hut, which is quite a anachronism. Second of all, they don't use clubs, but throwing hatches, knives and all kinds of weird magical weapons to defeat foes -but then, they ARE ninjas... They fight their way through tons and tons of enemies in order to free the stolen women!