You can choose to play as other characters than the standard dinosaurs in the Puzzle Mode. Just choose the Puzzle Game from the Selection Menu and when you're on the Map Screen, press Left, Left, Up, Down, then L1 + L2 + R1 + R2 simultaneously. A special character selection menu will come up. Cycle through the characters with the pad and choose a character with a button. You'll play the next round with the character you've chosen.