From the announcement:
Deep in the dark forest, cute critters gather ‘round, waiting for you to give them what they crave. Some of these devious creatures will try to fool you. Some will butt heads and scurry back into the trees. Others will stay no matter what. Gather your fireflies and see if you can lure the best ones to your side. Smile is available now!
Smile invites three to five players to enter the woods and hunt for the cute critters that live there. Tempted by the juicy fireflies that you carry, the critters just might come and join you…if you offer them more fireflies than your friends, that is!
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