It's very hard to explain. Press the button so that the foot touches the ground under your body (maybe I already said that in the tutorial, sorry, I don't know what else to say. Just try, try, try! :p )
No sorry, there is no Mac version. But would you be interested by a mobile version? Soon I'll start a beta test. You can give me your email address if you want to participate.
there are always specific problems in each platform which take time to solve
I used specific code for windows to make some part of the game that would need to be completely rewritten for Mac and I really don't have time for that. I prefer to concentrate on the iOS/Android version (release before the end of 2018!!)
