Yeah, it can be a bit unforgiving :D
Keep in mind that the fox will consume the rabbits in his mouth if you wait too long with throwing in fresh ones, basically eliminating all your progress. So make sure you throw them in at a steady pace!
The game is currently a bit unforgiving if you fuck up, I'll be looking into changing that after the voting is done. Also the victory state is a bit unclear, as the fox doesn't change visually etc.