Late reply, but apologies! Sometimes I forget to bring up the channel chat on my phone, and most of the time when I do, all the messages are just greetings, haha.
GrimGrimoire is a PS2 game by Vanillaware (makers of Odin Sphere, Muramasa, Dragon's Crown) and is heavily-inspired by Harry Potter, if you couldn't tell. It's a real-time strategy game. You either defend for x amount of time or try to obliterate your enemy's (computer enemy) runes and units, depending on the stage. The main character, Lillet, is repeating the same five days over and over again, trying to prevent some catastrophe...but each sequence of days has different challenges/stages, due to Lilith's choices being different each time she goes back in time.