Keepie Uppie Expert Achievement in Bluey: The Videogame

The Keepy Uppy minigame unlocks as part of the story, during the first episode.

As the name implies, you need to keep a balloon up in the air. There's a marker on the ground where you need to stand to hit it, and your hit counter is in the upper right. This takes no real effort, so just finish the game (it ends around 30 hits) and you'll unlock this achievement along the way.