This indicates the specific patch version of the game. Version 1.0.1 typically includes initial "Day 1" bug fixes and performance optimisations following the retail launch.
Because high-definition games are large, they are often split into smaller "parts" for easier downloading. This file is the first segment of a multi-part compressed archive; all parts are required to extract the full game. Safety and Ethics Warning The.House.of.the.Dead.Remake.v1.0.1.GOG.part1.rar
This version includes a "Horde Mode," which significantly increases the number of enemies on screen, and an achievements system to encourage multiple playthroughs. Deciphering the File Name This indicates the specific patch version of the game