Coming in at 5.2 gigabytes, you can download sufficient data of Super Mario Odyssey from the Nintendo Switch eShop in order to be prepared to play the full game when it launches around midnight starting October 27 by downloading an additional smaller download to complete the pre-load data giving you the full game.
The pre-load went live starting in Japan and slowly rolled out in every other territory. Super Mario Odyssey is the first game to feature a pre-load option for Nintendo Switch on a worldwide scale.
Soon it will be Odyssey time. Yessey.