Apparently cannot be played without a controller....one is "recommended", but thought that meant a mouse/keyboard could be used in a pinch. Apparently not.

Hi tommad, do you have a link to this info? It seems really odd not to support keyboard like Pinstripe did. I will wait and see if this is any different on the Linux release.

Actually it can, but I only discovered the way to do it while looking for a completely unrelated solution (capping the frame rate which was ranging anywhere from 400 to 1900 fps). [Also note that this was done with a DRM free copy I got from Itch.io, which I don't think will be different from a GOG copy].

Since the game was made using Unity, hold the shift key while starting the program, and it will bring up the config screen (see the attached file). There you can set the graphics quality to Beautiful (which has Vsync on), and (with respect to the keybinding problem) switch to the Input tab and manually bind keys for a keyboard. You'll have to play around with the setting to see which buttons (ranging from b0 to b19 and a1 to a10) do what. I tried it for a bit and frankly, it was a royal pain in the ass, and I just used my gamepad. Hope that helped.