Bronze:

COMBO KING!
Objective: Get 1 level combo star.

SPEED DEMON!
Objective: Get 1 time star.

DETECTIVE!
Objective: Find 3 hidden stars.

DANGEROUS!
Objective: Get a DANGER star.

MONEY GRABBER!
Objective: Get 5 coin dash stars.

STAY ON TARGET!
Objective: Get 5 target stars.

COLLECTOR!
Objective: Collect all mini stars on 8 levels.

BACK ON THE BIKE!
Objective: Complete the first tour.

SHARE THE FUN!
Objective: Send 1 level to a friend.

BEAT THEM AT THEIR OWN GAME!
Objective: Receive 1 level from a friend.

MEGA COMBO!
Objective: Get a x100 combo.

NINJA STARS!
Objective: Get 4 stars in one run.

Silver:

ALL THE TIME IN THE WORLD!
Objective: Get all of the time stars.

TRICK MASTER!
Objective: Get all of the combo stars.

AROUND THE WORLD!
Objective: Finish all levels.

MASTER OF DISASTER!
Objective: Get all the stars in the game.