Stars

I have earned a start but none of the plus buttons are working. Any help?

Only two bonuses are available for purchase when you earn your first star; the Gem bonus and the Detonation bonus.

You will see the "plus" sign is orange if the bonus is available for purchase or upgrade.

Hover you mouse over the bonus and a description will come up at the bottom of the screen. It will say "locked" if you cannot purchase yet.