Download the early version that somehow made it to the App Store before the official release date
The mistakenly-listed game has since been removed, with Ubisoft reps telling Touch Arcade that it not only was it an early release of Discovery, but it wasn't the final build, and thus may have had some bugs that will be ironed out by release. It was also incorrectly priced at $11.99. Just a big old whoops all around.
Even if you didn't manage to snag a copy of the game, Touch Arcade did, and the site courteously recorded some footage for us all. You can see that after the break.