Had to not only quit the game and replay the level, but had to refresh the browser a few times before lvl 3 worked for me. I think I had to play the level about 7 or 8 times. Finally did get the badge though! Thanks, Greg...
Tips for earning badge: Never "earn" the "T" bases, they only shoot things into you. The shield is your friend. Don't over-shoot the bosses--they hang around longer if you only slow them down, earning you precious seconds.
It took me several tries to "earn" the coin collector badge. I didn't think to take a screen shot the first time, I did the second time, but wanted to try it again since I knew which coin it wasn't accepting, and got the badge when I went back the third time, just for that badge. So, it does work, it's just picky...