It would play a lot like normal Mario Party, except the main characters would be Touhou characters. Stars become "Precious Things", and Items are replaced by spell cards, which can either have positive or negative effects depending on which one it is. Bowser Spaces are replaced with Flandre Spaces, and if you lose, flan destroys everything you have (Currency, Spell Cards, and Precious Things.). DK spaces are replaced with Suika spaces and retain their beneficial effects. There will be seven boards, each representing one stage, with the 7th and most difficult becoming available after completion of the first 6.
Minigames have different gameplay modes depending on the game, but there will be at least one bullet hell minigame and at least spellcard duel minigame. The movement system remains the same.
What if Flandre got coal for Christmas?