The official itch.io project page lists the update file size at approximately 1,023 MB . Context of the File Format
This file, "Roller Katz BF Episode 1 (NSP)(eShop).rar", is a compressed archive containing a digital backup of the Nintendo Switch game . Specifically, the .nsp extension indicates it is a Nintendo Submission Package, which is the standard format for games downloaded from the Nintendo eShop . Game Profile: Roller Katz BF: Episode 1 Genre: Action-Adventure / 3D Platformer. Roller Katz BF Episode 1 (NSP)(eShop).rar
This is the native format for eShop titles. While legitimate owners can back up their own software, these files are frequently found on community forums like r/SwitchPirates for use with custom firmware. The official itch