"Super Mario 3D World + Bowser’s Fury"

It looks like you're asking about a key feature or the main selling point for on Nintendo Switch (NSP refers to a digital game file format).

Super Mario 3D World + Bowser's Fury - Nintendo Switch - Games

Nintendo Submission Package

NSP stands for . It is the digital format used by Nintendo for games downloaded directly from the Nintendo eShop. Unlike XCI files (which are cartridge dumps), NSPs are often smaller and can include DLC and update patches.

Part 2: The Two Games Inside One NSP

Super Mario 3D World Bowser’s Fury Switch NSP

If you are emulating the on PC via Ryujinx or Yuzu, you can push this further:

how the game engine handles two completely different rendering and logic modes

The most interesting feature isn't just the new content — it's on the fly, without loading screens.

Completion of Bowser’s Fury takes roughly 3-5 hours, but 100% requires finding 100 Cat Shines.