GCREST (game developers) announced that they have started two anime projects for the smartphone game Yume Oukoku to Nemureru 100-Nin no Ouji-sama (eng. Dream Kingdom and the 100 Sleeping Princes) at the game’s Summer Festival 2016 event. A TV short anime in 2017 and a TV anime in 2018. You can read more at the official website.
Yume Oukoku to Nemureru 100-Nin no Ouji-sama was released in 2015 for Android (Google Play) and iOS (App Store). The purpose of the game is to wake up (collect) the 100 sleeping princes from Dream Kingdom voiced by famous japanese voice actors.
Experience the story and clear levels to gather crystals that you can turn in to get new princes. To clear levels you have to combine 3 or more orbs in five different colors to take down monsters. Each prince belongs to one assigned color (see webpage).