: The ".part10.rar" indicates this is the 10th segment of a larger, multi-part compressed archive. You need all parts (part1, part2, etc.) in the same folder to successfully extract the game.
In this context, a "feature" usually refers to the specific content or characteristics of that file or the release it belongs to:
: The name "Re77urn44l" is a coded version of Returnal (using numbers to replace letters to avoid automated copyright filters).