Onemorislnd-(usa)-nswtch-[base]-nsp-ziperto.rar [BEST]

The "proper piece" you are looking for—specifically how to use this file—generally involves installing it on a modded console. File Tag Breakdown

: The game title, "One More Island," a colony management simulator. USA : The region for which the game was released. NSwTcH : Shorthand for Nintendo Switch. ONEMORISLND-(USA)-NSwTcH-[BASE]-NSP-Ziperto.rar

: A popular multi-purpose tool that allows you to install NSP files from your SD card or via USB from a PC. The "proper piece" you are looking for—specifically how

: Indicates this is the core game file, not an update (v.0) or DLC. "One More Island