Free upgrade if you have Darksiders 1, otherwise 80% for launch
DARKSIDERS WARMASTERED EDITION FEATURES
Support for up to 4k video output resolution
Doubled all the texture resolutions
Re-rendered all cutscenes in high quality
Rendering improvements and rework
Better shadow rendering quality
Post processing effects
Optimized framerate
Wide Variety of Graphic Options (FOV, Postprocessing effects, Anti-Aliasing, Texture Filtering, Windowed/Fullscreen, etc.)
Steam Trading Cards
Native Steam Controller Support
How does free upgrade work? Just appear in your Steam library?