I've got Mizuki now both on Nutaku and Mothership. Didn't get her on Mothership after going through 3000 at first. Had to:

1. Whitelist in AdBlock Plus
2. Clear Cache in Firefox MacOS
3. Quit Firefox
4. Used the Forge to clear levels
5. Level again through 3000

Now I get ads on occasion but they do pay for us freeloaders…