luvthemgames: I did right-click, Properties:13.193 Files. I guess that's why it takes so long to install.
WingedKagouti: Terraria is also fairly well compressed.
The devs once released a patch where all the files were uncompressed and the game went from ~200MB to ~800MB.
It's not due to compression, it's because some idiot decided it's okay to have the game consist of well over 10,000 loose files, which hammers the file-system, storage device, and CPU which takes up more space on a drive while drastically lowering performance, rather than simply having all of it in even a simple zip file.
It's basically a worst of all worlds approach to doing things.