Its not just your copy dont worry. Its the usual kg fuck up. Atm from what i noticed beetween version (jp melissa was given for free by acerola a while back in dlsite):
The skip button is broken, more than half of the voice lines and audio files either dont work or are beign played in the wrong place, the uncensoring is obviously bad in some cgs(and no it wasnt made by acerola), quite some scenes just skip to "and they had sex" even if you never saw them before.
I believe someone posted in this thread that you can use the windows magnifier function to "increase" the size of the game window so you dont lose quality.