unity game file help

i lost the file from a game i was working on but i have an old build of the game is there any way i can use the old build

If you mean a script then you just need to open the NEW version of the game in Unity. In Windows (Iā€™m assuming you use Windows) open Explorer and go to the OLD games Asset folder, these are normally in Documents ā†’ Game Name ā†’ Assets. Find the script and drag it into your assets folder in Unity for your NEW game.

This can work for other files as well but I expect you mean a script.