According to Nintendo, it looks like tabletop and docked mode are the only ways you are going to be able to play Super Mario Party, and it sounds like a real bummer... until you put some thought into it, then it seems almost obvious.
We already could have guessed this, given that a bunch of the mini games use the Joy-Con gyro feature, and really, when would we be playing in handheld mode? Sure, there is bound to be single player content, and I suppose that's when you'd be using handheld mode, but there is a good chance that you aren't going to be buying a party game to play it by yourself, and most likely, if you are going to be playing this at all, you're going to want it on the big screen. I mean, the word "party" is right there in the name.
Here's the skinny from the Japanese website:
Play Mode:
- Tv Mode - Number of players: 1-4
- Table Mode - Number of players: 1-4
- Mobile Mode - Number of players: Incompatible
The original 4-player Mario Party series board game mode that fans love is back, and your friends and family are invited to the party! Freely walk the board: choose where to move, which Dice Block to roll, and how to win the most Stars in skill-based minigames. Wait till you see the 2 vs 2 mode with grid-based maps, the creative uses of the console, and the series’ first online minigame mode!
Test your skills in sets of five minigames with the new mode, Mariothon, and see how you stack up against players across the globe in Online Mariothon*. Whether you’re pedaling tricycles, flipping meat, or who knows what else, you’ll use Joy-Con™ controllers in clever ways across 80 new minigames; some are all-out free-for-alls, others are 2 vs 2, or even 1 vs 3! Toad’s Rec Room lets you pair up two Nintendo Switch™ systems**, which you’ll lay side-by-side on a flat surface like a real tabletop game. That way you can play a mini baseball game, battle tanks in custom arenas, or even see who can match the most bananas by repositioning the systems however you see fit!
Super Mario Party is the eleventh main installment in the Mario Party series and is set for release on 5 October 2018 for the Switch.