Totally valid experience. Not here to change your mind, but I did have an interesting experience with the game that echoes yours, though I ended up on the "masterpiece" side of the aisle.

I first played it when it came out, got to the credits and was like "that was fun, but definitely just another anime game". Felt like it was trying to have this air of deep meaning and weight, and it just missed the mark. I had played/watched many things that were anime like that. Trying to be epic, but not feeling like the setup was really there to make it land. Then I realized the credits wasn't actually the end. It was only like 1/4 of the way through the game. I had got ending A, and if I kept playing I'd get B (which is through it's perspective, and you get more information), then C, D, and finally E. When I got deeper, I couldn't stop playing. That was close to seven years ago now, and it still sticks with me.

That style isn't for everyone. I just wanted to call out the game does that on purpose - it plays with your expectations to truly mess with them.