Are you referring to the FPS? If so, I'd assume it's due to all of the steam features such as the menu that appears when you ALT+Tab and such, although I'm not a frequent steam user so maybe not. You could try executing the command "/opt fixedframerate 0" which should boost your fps.

As for you sticking with the steam version because all of your data is on there, you can easily transfer it onto the normal version of the game by going into your toribash steam directory and just c/p'ing the game files into the normal toribash directory.


Edit: My bad, didnt see the black square clearly on phone screen. But you can always transfer the files like Zwouter and I said.