Finished the game yesterday, and felt underwhelmed.
But now that I've slept on it, I think Uchikoshi just wanted to do something different from the Zero Escape series. I feel that the twists weren't as huge as in, say, VLR or 999, but in AI the story is more about characters and their development. It's more "human", in that the main element is the characters, their motives, their traumas, their feelings rather than hard sci fi and time paradoxes. It's a story where relationships take the center stage, love in the widest sense possible is the main point, imho.
I don't even know if I'd rank it higher or lower than the ZE series, it's just different. The gameplay is different and the focus is different, it's a more intimistic story that I'm very glad I experienced.