Gravity Falls: Legend of the Gnome Gemulets is a side-scrolling platform game. Players assume control of Dipper and Mabel, and they can freely switch between them at any moment during the game. The two characters have different abilities. Dipper can combat enemies with a close-ranged weapon called Gnome Battle Cuffs and look for clues using a flashlight, while Mabel can utilize a grappling hook to reach high grounds, and combat enemies with ranged attacks by her "Fleece of Bedazzlement-enhanced sweater sleeves".

In Gravity Falls: Legend of the Gnome Gemulets, a crisis has engulfed the Gnome kingdom – and only Dipper and Mabel can save the day. The Pines twins must work together to collect tools and weapons around Gravity Falls, as they attempt to solve mysteries and prepare for encounters with paranormal and supernatural creatures. On their perilous journey, they will have to battle fearsome enemies that will block their path, and ultimately restore order to the kingdom.