Chasm: The Rift

A Shooter game by Action Forms Ltd., released in 1997

Humankind, in the process of evolution, has encountered a mysterious phenomenon - the destruction of the normal flow of time. From the past to the future, time rifts are forming in Earth's atmosphere. These rifts lead to different periods of history. Through them the most aggressive creatures from the past, present, and the future, have begun to infiltrate our time. These mutants, known as Timestrikers, have begun a complete and systemic eradication of all human life. You are a specially trained commando who has been volunteered to investigate a recent attack by the Timestrikers. Utilizing an arsenal of devastating weapons and mysterious items from the past and the future, you have been authorized to terminate any mutant creatures that attempt to obstruct your investigation. Each assignment gets you closer to the heart of your goal. A mission briefing gets you moving in the right direction, but it's up to you to carry out your orders. Grab your weapon and report to the Commander immediately!