The file name indicates that the game was split into multiple parts (this being "part1") to make downloading easier. To successfully play the game:
The main story of Serious Sam HD: The First Encounter takes roughly 6 hours to complete, or up to 20 hours for 100% completion. Structure: The game consists of 15 linear levels . About the Download File download-serious-sam-apun-kagames-part1-rar
Find links to the where the game is sold. The file name indicates that the game was