Hi kittyrancher! I'm looking into this now and it looks like there's an issue preventing the opening animation that reveals the main menu from playing. The game is still running, but for some reason the screen never gets revealed so you never see the main menu. If uninstalling and reinstalling the game + rebooting your computer doesn't help, this may need a small patch to resolve - I'm still hunting down the exact bug that could be causing this and just wanted to let you know that we're still working to get this resolved!
Please let us know if you have any luck and we'll let you know as soon as we get a quickfix patch ready!