Pedal to the Metal Achievement Tips?

[MrLedZ]

I've unlocked the game 100%, beaten all the non-hero challenges, but I still haven't unlocked the Cyborg outfit (by collecting 10 stars in one life). It's driving me nuts; I usually can only grab 4-5 stars in a single life. Anyone have any advice?

[ScorpionSupreme]

You're more likely to get stars by blasting huge groups of blocks, so let them pile up.

[Vitamin Ex]

I'm stuck trying to get this as well, my best is 8 so far on the ice stage until I got hit in the butt with a rocket. I use Beezle because he's strong and jumps high, I know some people like to use the ninja because of the double jump but he's a bit weaker for clearing out blocks fast.

On a different topic, when I first got Beezle and tried this I got a message saying I unlocked a new outfit skeleton or bones or something like that but I still have a "?" box on my character screen. Is there something else I need to do to get him to be playable?