Is the incest activated from start or do I need to activate it through the console somehow?
Disabled by default. It changes some dialogs, nothing more, I think.
In disabled state, if I remember correctly, it makes you to an exchange student.
After starting a new game open renpy console (Shift+O) and change variable:
$ INCEST_FLAG = True
You can change it at any time in the game, but dialogs start to differ right from the start. Interestingly, when the flag is set to true, then when you first meet mom, she mentions an exchange student that occupied your room earlier, but "left in a hurry" :biggrin:
Right now the whole game is running in "blue balls mode" for the PC, don't expect anything but all kinds of peeking, groping sleeping girls, older sis and mom having steamy sex (separately) with older sis's boyfriend and the older sis flashing a boob at you a few times at the very end of her longest plotlines.
But dialogs are well written, characters are looking good and plot lines aren't bad, although almost all of them unfinished. It has potential to become a good game eventually. Right now it's a PITA to play without constantly fiddling with variables on the console, searching various strings in all the script files (I prefer to use grep in bash shell) and shuffling through the game script in Notepad++.
Like I said earlier, it looks like a typical "work in progress" game in an early stage.
Last but not least positive thing about this game is that the coder seems to be experienced in Renpy, we can probably expect a well working code and a minimal number of bugs despite of a complicated system of repeating events and progressing plot lines.