Underhell is a Source Engine game developed by the Underhell Team in collaboration with We Create Stuff. Underhell Chapter 1 requires ONLY Source SDK Base 2007 installed. No Source game is required.

tompa82 says

10/10 - Agree (4) Disagree

Awesome! Incredible depth of story, quality of voiceacting and feel of the guns! Cant believe this is a mod, it should be game in it´s own right.