The player takes on the role of an unnamed Marine whose mission is to stop the so-called Time Strikers, mutant beings invading different time epochs, from taking over the earth. On this mission, he visits places ranging from military bases in the present to Pharaonic tombs in ancient Egypt. All of the levels involve dark corridors, often like that of catacombs and crypts. One of the most notable features of the game was the ability to remove limbs from enemies. Still of interest are the bosses which can't be killed by mere firepower but instead have to be brought down using special tactics. Source: Wikipedia, "Chasm: The Rift", available under the CC-BY-SA License.