Midnfghtexp-(usa)-nswtch-[base]-nsp-ziperto.par...

Indicates this is the base game file, not an update or DLC.

A Nintendo Submission Package; the file format used for Switch games. MIDNFGHTEXP-(USA)-NSwTcH-[BASE]-NSP-Ziperto.par...

It is likely sourced from Ziperto, a site that aggregates game ROMs. Indicates this is the base game file, not an update or DLC