: New character movements and environmental interactions that weren't possible in the 2007 original.
This specific feature allows users with limited bandwidth or unstable internet connections to download the massive game file in smaller, manageable "parts" (like the part6.rar you mentioned) without needing to restart the entire 40GB+ download if a connection fails. Core Features of Call of Duty: MWR download-call-duty-mwr-apun-kagames-part6-rar
If you are looking for gameplay features included in that specific version: download-call-duty-mwr-apun-kagames-part6-rar