What do the spinning cards do in 100% Orange Juice?

Solution 1:

Certain cards are trap cards and when used they are placed on the board as a face down spinning card. If a player lands on a spinning card during their turn the card will activate and it's effect will be applied to that player. There is also a Field Event called "Minelayer" that will place a random trap card on the board every 3 turns when active.