itch.io

You just have to press esc then use your custor/mouse or arrow keys to the save then press enter/space. 

You could save it one of the slots below the auto save :> just use arrow keys/mouse then enter/space

I've only played the browser version, so I don't know if there's any difference in controls, but I've found that you can substitute Z and X for the Return/Enter and Esc keys, respectively. Also, you can use either of the Shift keys as your dash button.