How many levels does Astrosmash have?

[BassGuitari]

Does anyone know know many "levels" (for lack of a better word) Astrosmash has? I can get to 6X, but the game becomes all but impossible at around 200,000 points (for the curious, I just scored 208,680 pts...I think my highest score might be a little more though). I always use the autofire mode though...then Intellivision's controller clearly was not designed with action games in mind.

 

As far as I can recall, the screen colors for each level are: Black, Blue, Purple, Green/Blue, Gray, Black.