While version 1.05 of is primarily a technical update rather than a content drop, its most significant "feature" was the critical fix for StreetPass functionality .
If you are looking for gameplay content like or Keys , these were built-in from the start in the 3DS version rather than being added in later patches like they were on the Wii U. Super Mario Maker Update v1.05 3DS (EUR/JPN/USA...
1.05 (Released March 23, 2021) Addressed an issue involving StreetPass functionality. Nintendo Support How to Update Super Mario Maker for Nintendo 3DS While version 1
Because the 3DS version famously lacked the ability to upload levels to a global server, StreetPass and local wireless were the primary ways to share your custom creations. This update ensured that the core "Share" pillar of the game remained stable for the handheld community. Key Context for 3DS Version 1.05: Nintendo Support How to Update Super Mario Maker
: It was released on March 23, 2021 , specifically to maintain connectivity as other legacy services changed.