If you loved Kamen Rider W Returns: Kamen Rider Accel, try Kamen Rider W Returns: Kamen Rider Eternal
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
You already loved

Kamen Rider W Returns: Kamen Rider Accel
→
Try this next

Kamen Rider W Returns: Kamen Rider Eternal
What they share
Both films are directed by Koichi Sakamoto, and they both carry the playful mood tag, and they sit in Action / Adventure / Science Fiction territory. If that's the register that drew you to Kamen Rider W Returns: Kamen Rider Accel, the second film will land in a comparable space — through a different lens.
playful
What Kamen Rider W Returns: Kamen Rider Eternal is
You investigate a series of events and then a mysterious woman reveals a complex backstory but the director leaves it open to interpretation.