I’ll put a spoiler warning anyway in case people didn’t read the topic title.
One of the biggest problems with rewrite is the multiple worlds theory/different timelines that would make it difficult for an anime to be coherent and understandable. In addition, the visual novel is very, very, very long.
In order for the anime to succeed, it must be two seasons with 23 episodes each, much like Clannad. I would propose the following outline:
Season 1: The heroines
Episode 1-2: Beginning of moon arc. I think this is a good way to introduce some mystery and suspense. Episode 2 should finish off with Kotarou being able to understand what Kagari is writing down, and this is a good segway into the common route.
Episode 3-5: Common route.
Episode 6-8: Kotori’s arc.
Episode 9: Should return to the moon arc, where Kotarou begins examining more timelines:
Episode 9-11: Chihaya’s arc.
Episode 12: Should return to moon arc once again, where the moon arc advances further and Kotarou examines more timelines…you should get the picture now so I’ll omit saying this again.
Episode 12-14: Lucia’s arc
Episode 15-17: Shizuru’s arc
Episode 18-20: Akane’s arc
Episode 21-23: Finish off moon arc, setup for terra
Season 2: Terra
Maybe this should only be 13 episodes, but Terra is pretty fucking long, epic, and amazing. Still working this out…