SpaceMarine Tweaks 40k for OpenXcom is an innovative mod designed to enhance the gameplay experience for fans of the Warhammer 40,000 universe. This mod focuses on transforming the Space Marines faction, particularly the Deathwatch, into formidable elite soldiers with a comprehensive upgrade system. Players can expect a complete overhaul of the Marine upgrade tree, taking Neophytes through to Veteran Terminators, along with the introduction of new soldier types such as Librarians and Chaplains, each equipped with unique abilities and gear.

In addition to the new soldier types, the mod features significant reworks of armor and weapons, ensuring they are more fitting for the elite forces of the Emperor. New scripted abilities enhance the survivability of Marines, while a Fire Support system allows for precision strikes on the battlefield. Additional features include smoke launchers for crafts, customizable turrets for Razorbacks, and a redesigned process for hiring Deathwatch Marines, promoting the formation of a super-elite Kill-Team.