I am NOT one of the developers, so I can't answer your question. It does, however, raise one for me.
I'd have to ask you, WHY you'd want it on Steam. You can play on Mac, Linux, Android or Doze. What other platform is there? Erm...playstation? Why? Seriously! I'm not belitting, ragging, or cutting you down. I'm asking. I don't understand. Really. You found the game. Why do you need steam?
I generally steer clear of any game where I need to log on to play. I guess that stems from way, way, WAY back when, when it cost you for the time you were connected. It was something like ex minutes per dollar and could get quite costly. So, when I have to log in so that I can play games, I don't buy or download the game. I don't understand why you would. You even get to watch adverts while you play! No! Not for me. DRM Free or not at all. Thank you very much. I'm seriously puzzled why you'd need a gaming platform for a game you can play wherever and whenever, no accounts necessary. Download the free version here, extract it and play. Could you explain it so I can understand your question? Please?