The file you downloaded is likely just the update patch (a .xdelta, .ips, or .exe file), not the full game. Here is the proper install order.
Resolved a major bug where the Dog Princess's orgasm state would not end and fixed save data conflicts related to sleep states. eng the demons stele the dog princess v2 upd
The upd file is usually an .exe patcher. Run it and point it to your copied game folder. If it’s a .xdelta file, use (free tool). The file you downloaded is likely just the update patch (a
The update includes several new features and changes, including: The upd file is usually an
The update for The Demon's Stele & The Dog Princess (specifically referring to the Unity version "v2" or transition from Flash) introduces several new features and system overhauls. Key Updates & New Features The transition to the Unity version (Alpha releases) includes the following additions: New Gameplay Mechanics Finger Play Hero Functions : Implementation of the function for the player character. Visual Enhancements X-ray Section Function
Updated missionary positions to allow for more interaction, such as opening/closing legs or undressing.