That initial download will give you access to only a limited portion of the game (although you will be able to try all three of the game modes).
Indeed, Let's Play Video Games reports that this game will feature "a 3D open world hub from which different worlds can be selected, with multiple objectives to complete in each, much like Mario 64 or Mario Galaxy".
That sounds pretty great, but it casts doubt over the chances of Super Mario Run launching on Switch at the same time.
It's a Universal app - one app will work on all compatible i OS devices, so once you download it for i Phone it will become available for download on i Pad.
(Not that this makes a huge difference, since the game is free.) We assume that in-app purchases made on one device will be transferable to other devices using the same Apple ID, although this hasn't been confirmed yet.
Read next: Best i Phone games | Pokémon Sun & Moon review Super Mario Run launched on the i Phone on 15 December 2016! We were given an embargo of 6pm on the 15th for publishing our Super Mario Run review, so we knew it would be launched on the UK App Store after that; in the event it arrived late in the evening here in the UK. In an interview with Bloomberg, Nintendo president Tatsumi Kimishima was asked about his expectations for Super Mario Run.