Watched “Infinity Train” (Cartoon Network, HBO Max), a series about doing the right thing and acknowledging your problems. The setting is a mystical giant train, apparently endless. The wagons of this train contain a variety of whole fantastical worlds. The main characters of the first season (a girl named Tulip, the robot One-One, and the king of Corgania, the talking corgi Atticus) are looking for a way out of the train. By the way, the character is voiced by Ashley Johnson, who voiced Ellie from Last of Us.
2 seasons (third season starts in August).
10 episodes per season ≈ 11 minutes each.
One season is one complete story.