Is there a way to alt-tab out of this game or play it windowed?
Let me upload a new version with a fullscreen toggle key. I'm still working on an actual in-game interface for graphics options but this will hopefully work okay in the mean time. F4 will allow you to toggle it between windowed and fullscreen. You'll also be able to resize the window from the default 640x480 size. You can still switch between windows if you pause the game.
Unfortunately, alt-tab and alt-ctrl-del seem to freeze the game and force you to close it with the task manager; I'm still researching the problem and will hopefully find a fix for that soon.