Some nice features, but watch the ampitheater-type rooms! Lots of ornamentation.
Hope you like lava. (Lots of good stuff to find, if you look hard enough...)
An annoying infatuation with elevators, rooms that are *way* too tall (this is the first time I've felt vertigo jumping off a ledge in Marathon) and an incompatibility with 680x0 macs makes this one hard to recommend.