I also started and finished it this summer. It was really good. The whole game felt like a mix of 3D Zelda games (easy dungeons if you use the map), Persona 4, early Terranigma & Shadow of the Colossus (Racing against time, Towers, Saving your girl) and pre-4Biohazard (menus, papernotes about enemies and the story, limited inventory, fixed camera)
Ceres is voiced by Noto Mamiko. I’m not a big fan of her or anything but it sure felt like I was married to her, speaking to her like that every day and giving her gifts, it wasn’t a bad feeling. I grew really attached to Ceres, I didn’t let her transform once besides the game’s beginning. Meaning I imposed myself a smaller time interval between my trips to the tower and my retun to the observatory. Well the game is easy if you know what you’re doing. Reminds me about how I saved some people in P4 the day they got into the TV (most notably the girls characters), or like how you’d never let anyone die when playing a Fire Emblem. I just can’t leave them alone.
I got the S ending on my first try. It sure was satisfying. The guys at Ganbarion sure did a nice job with the story. After that, I watched the bad endings on Niconico/Youtube, they sure made my heart hurt. They’re pretty heart wrenching, especially the C one. And well, the D one is so screwed up it’s almost funny.That was a really great game. Too bad it doesn’t seem that popular. There’s like only 5 pages on fanart of it on Pixiv.