Deus Ex is the first in a series mixing action and RPG play by Warren Spector, the creator of Ultima Underworld and System Shock. The world is in chaos. Terrorists roam the streets. The reemergence of an ancient secret society bent on world domination. Playing as rookie UNATCO agent J.C. Denton, you will use your nanotech-enhanced body and mind to fight the enemy in this Unreal engine-based action/RPG hybrid. Denton improves his skills, receives additional bionic enhancements and plays with many sorts of equipment as the game develops. The intriguing story takes you from New York to Hong Kong, from Paris to secret labs, for over seventy hours of exploration. A software development kit has even been released so people can develop their own adventures.
Just mount up the file / burn it. Install it and play!