Found a bug. I searched all of the Mall squares, and when I reenter it, they're all uncovered and have bugs in them, but it tells me I'm 35/36 for the mission completion, so I can't unlock the Bridge and finish the game.
So I managed to just glitch the game somehow. On my home computer, I got to level 4. I just started playing on my work computer, so I was starting over again at level 1. I beat it, switched tabs to look at another site, then came back to Kongregate. When I clicked Complete to end the level, nothing happened except that I suddenly had achieved the card challenge. I reloaded the page, and the game now says I've beat every level up to 11.