У вашего броузера проблема в совместимости с HTML5
To unlock the true ending you need to beat the game without feeding on a single person. This is effectively "hard mode" and certainly limits the way you can progress/what you can do but at least the reward was more than just a trophy/achievement.
Also, did anyone else automatically assume what the bad ending would be based off the interaction? As soon as I beat it I loaded a older save and went out of my way to unlock it. Needless to say, it met expectations.