The ASSETS file extension is very commonly used. ASSETS files contain game resource files such as textures or 3D models. 55% of ASSETS files belong to Unity 3d assets. These are binary files without text. ASSETS files are seen when building a Unity project or modding a game. To modify gameplay like characters or environment, edit ASSETS files then replace them. Ensure ASSETS files are complete and error-free. If obtained from third party, ask for another copy. Errors may occur when copying files. Use Unity Asset Explorer to view and extract ASSETS files. Extract data like textures to work with in Unity. What ASSETS files are has been explained. Information on opening, viewing and converting them is provided.