Unfortunately, I couldn't find any specific information about a popular or well-known Steam game called "Adder". However, I can try to help you with some general information or suggestions.
These utilities are designed to streamline Steam’s built-in "Add a Non-Steam Game" feature. They help you integrate games purchased on other platforms (like GOG, Epic Games Store, or emulators) into your Steam library to use features like the Steam Overlay and Steam Input. steam game adder
A lightweight utility that scans your drives for installed titles and suggests clean shortcuts for your library. Epic Games Store
import requests
You can run the script, enter the required information when prompted, and it will attempt to add the game to the user's library. enter the required information when prompted