This guide explores what Unity files actually are, the different types of viewers available, and how to choose the right tool for your needs—whether you’re a gamer, modder, developer, or 3D artist.
If you are the developer or have the project files, you can import or open the assets directly: unity3d file viewer
archive files (the legacy web format) or creating a custom file viewer tool within Unity for users to open files at runtime. This guide explores what Unity files actually are,
Unity does not have a built-in native file explorer for standalone builds. You should use a wrapper or package: opening .UNITY3D files w/demo - Unity Discussions the different types of viewers available