If you are looking for an , here is a brief overview of why Portal 2 is considered a masterpiece of game design and narrative: The Convergence of Narrative and Mechanics
It looks like you've provided a file name——which is a common naming convention for a split compressed archive containing a Nintendo Switch game file (NSP) intended for use on modded consoles or emulators. Portal 2 (NSP)(eShop).part1.rar
For those looking to play on the Nintendo Switch, the game is officially available as part of the . You can download it directly from the Nintendo eShop . Portal 2 Local Co-op: Couch Fun For Two Players - Ftp If you are looking for an , here