I tried the opening of a solo match on desktop. My first instinct was to click the Cooperate / Defend / Betray labels along the bottom, but I couldn't tell how to change my intention while the 15-second timer was running. The How to Play page made it clear afterward: swipe left or right. A one-line prompt above those labels during the first round could get a new player into the interaction before the timer runs out. I only tested the opening, not a full match or online play.