Demo (JCv1.0.4.4) is broke as hell. No way to heal in town, so if you reach 0 hp in the forest, you are stuck at 0hp. And since you are stuck at 0hp, all battles auto-lose at the start. Mouse's boobs detach and reattach themselves during hscenes. Once Mouse' arousal reaches 100, Jessica can no longer have a turn because Mouse skips Jessica's turn - this causes hscene loop and lose the battle back to town with 0hp - whereafter the game is essentially over because you cannot heal in town. The church also doesnt work (supposed to reduce lust).
The demo should really be playable imo. Doesn't leave a very good impression, apart from the potential the game has.