German Fortress 3D

The year is 1944, alternative history of WW2.
The Nazis are going to commit the first combat launch of FAU-2. The USSR and the USA got a concrete intel about the position of the missile and its technical data. The weapon of hell is hidden somewhere inside a german fortress, called "The Beast".
Infiltrate the facility and find all the possible data about the missile and the unit itself to prevent the end.