I really want this game for months now but my parents only allow me to buy games off steam. I don't have a PayPal account or a card, I only have steam wallet money. Is there another way I can buy this game? Or when will this game be on steam? 

Unfortunately, the only way to buy it right now is over this page. I am planning to release it on steam but it will probably happen only next year. If you don't want to wait, please write me an email and I will see if I can find another solution for you.