[Balzac]

Because we have precedent in the anime, it's a fun pastime to idly speculate on how the game would turn out.

It would be very ground-breaking if instead of the traditional visual novel format of a common route with a set "start" leading in to individual routes, there'd just be Otonashi meeting the SSS and then urged to go on missions. So there's a central hub, which is Yuri's office, where one can pick out missions. The missions might be like Rewrite's Mappy which were freely optional and involve different kinds of minigames, but each mission is actually a developer ploy to establish flags to lead to individual routes. But instead of routes, they'd be character studies, giving the player, as Otonashi, insight on the nature of the afterlife. (people moving on, etc.)

It could go that finishing a route doesn't mean ending, perhaps one is not punted back to the start to begin a new game or load a previous save. Instead the player might be returned to Yuri's office and offered more missions? Leading to another character to explore.

Of course, the plot could start moving forward after finishing one or two characters, the escalation of the war against Tenshi, the arrival of Naoe, the disappearance of key members, befriending Tenshi and her powers going awry, etc.

And then boom, big "epic" conclusion involving an all-out war against the shadows that isn't constrained to episodes 11-13, hopefully with a better mastermind than the guy who lives in the basement. (With a different base as been stated in the above posts, the afterlife might have a different goal to reach or master altogether)

With Key, in their main games at least, there is always something new. Whether it's disjointed narrative but with a set purpose (AIR), lightball/points system mechanic and the establishment of an "after story" trunk route (CLANNAD), or minigames that are fun to play and aren't required (Little Busters!, and then the shift to new writers/paradigms which, even as they follow the tried and tested formula set by previous games, still end up being something refreshing and "novel". (Rewrite) I look forward to the "something new", barring unfortunate delays and acts of God.