It's a .zip file that need to be extracted because is a game jam submission that requires that the source is also included, but there is an executable file. Extract the .zip then open the Windows folder and click Astral Renegades.exe
oh it's in the windows folder. thought that all those folders jsut had the game files in it and that the .exe would be in the upmost folder (basically that it would be among thefiles we can see on your screenshot).
Extract the .zip then open the Windows folder and click Astral Renegades.exe