I think the right balance between player exploration and impetus for the story to be completed can be struck, the game exists as an endless summer but in the finished product I feel like giving stakes and risks for the story is important, and I think we can find the amount of time/days in game where it's a factor but not a stressful one for the player to consider
You could just have Lilith plant an explosive device somewhere within the city limits, only giving Jon clues when he taps another ass.
I've set the final scene for you.
Leslie *biting her lip while staring at Jon's massive wang* I know it's to save the city, honey. Will you respect me in the morning?
Jon *staring at her boobs* Uh-huh
Ashley *drooling on the floor in a puddle of cum* Soooo goooooooodddddd
BUT!!! Plot Twist!!!
While riding Jon, Leslie grabs an invisible Lilith, kissing her on the mouth and rubbing her butt. Leslie is an angel, and she's known about Lilith the whole time, just playing dumb. She convinces Lilith to stop the bomb by licking her clit. Jon becomes the emperor of the world thanks to the Savage Wang. I get more Ashley and Goth Chick scenes.