oh no, it seems you kept getting sent to the "procedural generators" screen, which is just a little demo reel of how the levels are created. You can hit the space bar to exit that screen. on the main screen are two options to start a new game. I think what might be happening is the mouse drift is placing the cursor over the "generators" button and then its loading that screen instead of the game.
You can try putting the cursor over the "New Game" button before hitting the space bar or mouse clicking.
I've had reports of the drifting mouse issue from Firefox users and I was able to replicate it but I'm still trying to figure out why its happening