I'm here to rep Gunslinger Girl. The original light novel is 14 or 15 chapters and the anime adapts only the first 4. A Hitman 2016 style game where you could get in, assassinate your targets and get out like in Hitman cleanly would be a sick gameplay loop to base a game on. There should also be combat missions too, because that's part of the story (they raid several safe houses in the anime, one being in the first episode).

A Symphogear action RPG or Musou, just to pull the crazy moves from the show (and some good yuri).

A Nanoha tactical turn based RPG, taking control of most characters like the Takamachi Harlowns, the Yagamies, Teana and Subaru, etc. plus having something like supports from FE and skits from Tales for family bonding moments and the like.

No. My imagination is very poor.

Code Geass RPG

Durarara!! game in the vein of Yakuza but you can play as all the main characters

I love this idea too.

Soul Eater (Manga)

A third person My Hero Academia action-adventure game would be my dream, it should have a good combat system but focus more on the exploration of the cities to find out where the villains are and on interactions with other students in order to unlock new moves and/or change the flow of the story

You live in the past.

An Ooen World huge Harry potter game where you can travel around Hogwarts, London etc and decide which faction to support stuff like that.

I'd like a Ghost in the Shell game for the PS4, I think that could be well-done, since I've heard good things about the PS1 game.

Would still be great.