I've added the auto window resize function to the macOS build, other builds will be updated later today. The game window should be resizable, can you try to maximize the window see if that fix the problem temporarily?
Update: Unfortunately during the GMTK Game Jam voting period I am not able to make any changes to files, but you can find the binary build on GitLab repository here if interested: https://gitlab.com/yxt0531/projectonlyone/tree/master/Exports