Hamtaro – Rainbow Rescue – Gameboy Advance

Hamtaro - Rainbow Rescue - Platform: Gameboy Advance

Unlimited Acorns:
-----------------
Press Up, Down(2), Left, Right at the 'Press Start' screen.

Secret Coloring Picture at the Clubhouse:
-----------------------------------------
Stand in front of the blackboard in the Clubhouse and press the A button. 
After reading the message, press the L, R, A, B buttons in this order and 
you'll receive a secret coloring picture.