Shatp! The bug is you played the first version on your machine, and the FOV slider is bugged way below the normal point. Simply start the game, check your options and make sure your FOV setting isn't set to the negatives to fix the odd bug where everything is dark.
For some reason the settings are all glitched out, including the resolution, I assume it kept some old setting from last time you booted up, holding onto something from the previous version.
However, I did find 2 bugs so far
1: after you maxed out love with Mom, if you go to grab her ass after dinner, the game sits with text and you cant click away
2: same issue after getting a BJ from sis at night, MC says "I'm not going to last very long" and I cant click anything else except camera options
This game is amazing btw, love how it's coming along so far!