(using Demo.zip) I can't get past the first barrier. It instructs me to "press left or right mouse button go grab the dark rocks" but clicking does nothing, and aiming at the dark rocks does not change the crosshair to the "grab-able" icon. Mouse works for starting menu and settings menus.
Okay! I didn't realize I had to get that close. I did get further, but got stuck after completing the third mountain -- it asked if I wanted to come home or stay ("press space bar to confirm") and didn't react to any keypresses or mouseclicks. I could still hit 'esc' to get the menu. May I make a feature request for save-game, so i needn't do it all in one sitting?