The Undefeated Deluxe Pack contains:
* Official 74-page Guide
* 7 Wallpapers 1600x900
* All Character and Important NPC Artworks
* 2 bonus Savefiles (Badass and God Modes)
How to find the deluxe contents
From your computer, go to:
C:\Program Files (x86)\Steam\steamapps\common
Then select the game folder.
Or directly from the Steam Client, first right-click on the game, then select:
Properties > Local Files > Browse Local Files
EXAMPLE