After the events of Attack the Light!, Steven, the Gems and their friends go on a quest to retrieve the Light Prism when it is stolen by the Homeworld Gem Hessonite (voiced by Christine Baranski).
Save the Light features seven playable characters from the series, Steven, Garnet, Amethyst, Pearl, Connie, Greg and Peridot, with an eighth character to be added in a future content update; four characters can be equipped to a party at a time. The game has a "blend of real-time and turn-based combat", and more of a focus on exploration and puzzle-solving than its predecessor. Players are able to explore Beach City and surrounding areas, and engage in battles with enemies. During battle, the players' actions, which include attacking and defending, will build up the star meter which allows the characters to pull off more powerful moves. A new feature allows characters to build up a relationship-based meter during battles and dialogue interactions; when filled, characters are able to fuse, such as Steven and Connie into Stevonnie.
Source: Wikipedia, "[en.wikipedia.org/wiki/Steven_Universe%3A_Save_the_Light Steven Universe: Save the Light]", available under the CC-BY-SA License.