To understand why a 13MB file cannot be the full version of GTA IV, we have to look at the raw data.
While the "GTA IV 13MB" download is a fascinating example of what compression can do, it is rarely a functional way to experience Liberty City. For the best gameplay, it is recommended to use the official Rockstar Games Launcher or Steam versions to ensure all assets, music, and security patches are intact. Gta Iv Highly Compressed Pc Game Only 13mb 15