I have Alienware 15 R3(1980x1080 screen) and I'm using the built-in keyboard. I can able to navigate up and down(play and quit) but can't select it. For selecting I tried "Enter Key" and "Left Mouse Button". And tried pressing all the alphabet keys.
Ah I see...I'm going to assume pressing Spacebar did nothing then in that case? That is the current default binding for confirmation. I can push a build with the enter button as another option to confirm.