The only catch here is that you should have already completed the entire story mode.
Although it's worth noting that as of right now, Nintendo have still not confirmed or denied this rumour, regardless how blatent it is. Here's a list of all the new software that Nintendo fans can expect.
We'll let you know more the moment we find out.
Talk to Luigi in any of the kingdoms to start playing. It adds new outfits and Snapshot mode filters, as well as a whole new minigame, called Luigi's Balloon World.
Take a look at the full listing of changes on the official website.
Once you've finished the game, Luigi will begin appearing in different kingdoms, offering Mario new challenges to complete.
The biggest addition that the update brings to the table is definitely the Balloon World mini-game, which has players either hiding or finding balloons throughout certain areas in the game.
Also included in the update are a range of new outfits and Snapshot filters created to give Mario a whole new look. Outfits don't have any effect on gameplay, but you happen to be a completionist, you now have a few more collectables to acquire in Super Mario Odyssey. Rounding out the update is a new pair of filters that you can use in Snapshot mode: Coin and Neon. It sounds like a pretty fun time, like an online hide-and-seek of sorts. More new outfits are planned to be added, so stay tuned to the Nintendo Australia Twitter account for more information.
A content update for Super Mario Odyssey was announced in last month's Mini Direct, set for a release in February, but a firm date wasn't set.