You are not doing anything wrong, while building the game in HTML the codes got mixed up and the forks don't spawn anymore, I am looking into fixing this.
It seems that when building the game in HTML the scripts got messed up and no forks were spawning, i might fix this in the future as well as the resolution. Thank you for giving your feedback!
Thank you for your review, I will try my best to add updates with options, and better visual effects, as for other modes it's probably better to make different games.