The main four go to outer space to find a star so Stumpy can name it after his girlfriend Ursula to celebrate their two-week anniversary.
"Let's Play Astronauts" contains the following tropes:
- All Just a Dream: At the end of the episode, we find it was all a dream Stumpy had, the events of which he is narrating to Kaeloo.
- Alternate Universe: The main four find one where Alternate Universe!Kaeloo transforms in reverse, Alternate Universe!Stumpy is a genius who likes math and hates comic books, and Alternate Universe!Mr. Cat and Alternate Universe!Quack Quack (known as Meow Meow and Mr. Duck) have Swapped Roles.
- Bizarro Universe / Mirror Universe: See Alternate Universe above.
- Freudian Couch: Stumpy lies on one while telling Kaeloo about his dream.
- Other Me Annoys Me: Stumpy's math-loving, comic-book hating Insufferable Genius counterpart annoys him to no end.
- Space Episode: The main four go to space in a spaceship.
