Hey, thanks for trying it out!
Could you elaborate on what you're pressing, and whether you're using a controller? I can use arrow keys and spacebar to interact with the buttons fine in a Kubuntu VM.
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.