Update 1.4.0 expanded the game's multiplayer and bonus content significantly:
Disclaimer: This blog post is for educational purposes regarding file management and software updates. We support the developers and encourage purchasing legitimate copies of software. Luigi-Mansion-3-NSP-Update-1---40-1--41-.4.0-Mu...
: Notably, this update patched the famous "Amadeus Skip" on the 4th floor, leading speedrunning communities to split their leaderboards into "Legacy" and "1.4.0+" categories. Emulation Context Update 1