The physical releases for Nintendo Switch games will come on cartridges similar to those that pop into your Nintendo 3DS, albeit much larger in their respective storage capacity. Compared to optical media no doubt the production of these game cards/cartridges would be a lot more expensive to produce, and in keeping up with modern devices digital version will also be made available. Here's a quick rundown of the expected download sizes.
- The Legend of Zelda: Breath of the Wild - 13.4 GB
- Mario Kart 8 Deluxe - 7 GB
- Snipperclips: Cut it Out, Together! - 1.60 GB
- Disgaea 5 - 5.92 GB
- Puyo Puyo Tetris - 1.09 GB
- I Am Setsuna - 1.40 GB
- Dragon Quest Heroes I·II - 32 GB
- Nobunaga’s Ambition - 5 GB
With the on-board storage of the Switch sitting at 32 GB (minus the operating system), its pretty clear that you'll probably want at least double that in expandable memory. Right off the bat, Dragon Quest Heroes will straight up require the presence of additional storage. And as physical versions of games wont need to be installed on the Switch prior to playing them it brings up the situation for a game like Dragon Quest Heroes where it makes more sense to buy the game rather than buy a separate card to store a digital download of it.
Confused? Well, the basic premise is this. If it's a large-scale release for the Nintendo Switch, you should buy the physical version as to avoid any potential storage problems.