Play with your Peridot by playing fetch! To play fetch, open your backpack and tap on a toy, like the Tennis Ball. Drag/swipe and release to throw it for your Dot. Your Dot will run, fetch the toy, and bring it back to you!
Toys will wear out after multiple uses. Forage in any terrain to find new ones. You can carry multiple toys of each type in your backpack at once, so be sure to stock up!