In the game Insaniquaruim, has anyone reached tank 6-1?

Question

I didn't even know the game had a tank 6 but after defeating the alien at the end about 6 times in a row, I suddenly got tank 6-1 when I went into Bonus Adventure (After you complete all the tanks and beat the alien at the end you then get a Bonus Adventure.)

Answer 1

I haven't gotten that far, but thanks for the info :)