Thanks everyone for the responses! I'd received too many, that overwhelmed me. I will go through them later.
Today the group had a meeting where we decided what kind of game to have. Some shipwreck-themed casual game with minigames. That involved some voting and me accepting that sometimes others have better ideas. Everyone assumed I'm the leader.
But later this day, one of us got angry on minigames! He wanted to have none of them, and he holds a grudge on me specifically. How to handle him?
To clarify, my goal is to keep the fun in making this game, and not making me sad or angry, or any of the other team members. The grudger is sad and angry already. The second goal is to actually ship the game by the deadline.
Accepting his design is not what we want. I can accept him leaving the team, but others might not, as some of them have more empathy than me.
I'm learning to be a better leader.