Freedoom is an open-source first-person shooter game that offers an alternative to Doom's copyrighted assets, such as textures, sounds, and game levels. The game is entirely free and open-source, which makes it an excellent option for those who want to play without spending any money.

Freedoom is a fork of nvllsvm's GZDoom-Android port and is compatible with most fan-made "WADs" (game levels) in the idgames archive. It offers an original and community-created set of assets and game levels that are open-source.

The game's interface is user-friendly and easy to navigate. Most custom WADs can be played by placing them under Freedoom/config/wads, selecting the desired WAD from the main screen, pressing "Addons," "WADS," then the desired WAD, and launching the game.

This project is not affiliated with Id Software or parent companies, Bethesda, or any relevant publishing companies. The game is available for Android users and can be downloaded from the developer's Github. Overall, Freedoom is a fantastic open-source alternative to Doom that offers a wide range of features and compatibility with most fan-made WADs.