Bronze:

Dinner Time Dino
Objective: Eat more than half the steaks in a single player game of All You Can Eat!

Catch of the Day
Objective: Catch all sizes of fish and win in a single palyer game of Ice Fishing.

Eat My Dust
Objective: Lap an AI controlled opponent in a single player game of Elastic Racers.

Hop, Skip and Dino!
Objective: Win every round in a single player game of River Crossing.

Easy Rider
Objective: Win a single player game of Hitch A Ride!

Silver:

Greedy Dino
Objective: Eat all the steaks in a single player game of All You Can Eat!

Fishing Frenzy
Objective: Catch more than 340kg of fish in a single player game of Ice Fishing.

Ace Racer
Objective: Win a race without spinning out in a single player game of Elastic Racers.

Mother Thumper
Objective: Hit stalactites in a row with the highest power smash in a single player game of River Crossing.

T-Rex Rambler
Objective: Never fall off and win a single player game of Hitch A Ride!

Gold:

Prehistoric Perfectionist
Objective: Win a standard single player game with the difficulty level set to hard.