You control a small group of NATO soldiers, headed by Cole Sullivan, a commando with extensive scientific knowledge. Your task is to investigate the mystery behind the sudden appearance of mutant creatures in Lublin, a small Polish city. Lublin used to house Gorky 17, one of the old Soviet "secret cities", which has been destroyed by the Russian military for unknown reasons.
There are two modes in the game:
A real-time exploration mode during which you can navigate your party members through the city. You can also interact with the surroundings in a point-and-click manner.
A combat mode, in which you engage in turn-based tactical combat, trying to eliminate the mutant enemies. You can use all kinds of weapons and ammunition you find in your surroundings. Furthermore, different weapons have different tactical effects.