I'm sorry the game was too long for you. There is now an easy mode where you can skip Professor Mia's punishments, allowing you to fast-forward time without consequences, going much faster. Maybe that will help you improve your gaming experience and give it another chance.
Regarding making a shorter version of the game, I'm sorry, but I have no plans to do so at this time. I could make it a kinetic visual novel (the only type of visual novel I know how to make right now) by focusing only on the main story, but that would miss a lot of romance options with main and secondary girls, and right now I have a lot of projects open to I think it is better to spend time.