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.

killer1978 says

10/10 - Agree (2) Disagree

mod is amazing ive experianced a great storyline, skins and alot more 3 words Best Mod Ever!