The original release of the game.
Released 2/27/2015, version 1.1 was released to fix various issues with the game to make it more "enjoyable". Changes that have been noted are as follows:
Introduced in 3DS firmware 10.4, some games are required to be on the latest update to launch. MM3D does NOT require 1.1 to launch. If you do update, you can simply delete the patch data by going into your data management settings and deleting it.
The latest North American cartridges of the game come with the 1.1 patch preinstalled. Due to this, it can't be deleted and it is recommended to buy the digital eShop version instead.