OH. i was under the impression the chapters themselves were going to be the seasons, like all of chapter 1 would be spring and then chapter 2 would be summer or something.
Nope. Each chapter is a full year.
If all the seasons are implemented at the start, how long is each one before rolling into the next?
Player decided. The general gameplay loop is gettin' gud and building trust with your teammates. You can skip girl stories and side content once you hit the minimum trust threshold to move onto the next season.
Some special events are unique to seasons though. There will be a "pool" of events and character dialogue that check for conditions. Like being hit with a snowball won't happen outside of winter. Neither will discussion on winter holidays. People will keep mentions of heatwaves to Summer.
a lot of replayability which is always nice
We're going for the telltale experience. Not quite there yet but our beta testers can confirm that the intro alone has like 15 different combinations depending on your choices during character creation and your general behavior.
How's the sex gameplay? Is it freestyle like Roguelike or does it just have some images and animations like every other H game?
Yes. There will be scripted sex scenes, still CGs with narrations, and freestyle.
For transparency, sex has been one of the harder things to program but we'll be adding and building onto it as time goes on.