PS4Switch GrimGrimoire OnceMore second trailer Learn the basics of the battle system. Publisher Nippon Ichi Software and developer Vanillaware have released the second official trailer for GrimGrimoire OnceMore. The trailer, dubbed the “Lesson” trailer, teaches viewers the basics of the battle system, which is focused on summoning familiars by the power of grimoires.GrimGrimoire OnceMore is due out for PlayStation 4 and Switch on July 28 in Japan. Read more about the game here. Watch the trailer below.