Complete level 4 of the indicated training game to unlock the corresponding new training game.

Alien Attack: Complete Meat Defender level 4.
Avalanche: Complete Zoo Feeder level 4.
Count Mania: Complete Avalanche level 4.
Court Curling: Complete Pot Shot level 4.
Drum Topple: Complete Alien Attack level 4.
Meat Defender: Complete Pirate Wars level 4.
Pin Crusher: Complete Court Curling level 4.
Pot Shot: Complete Block Buster level 4.
Zoo Feeder: Complete Shopping Dash level 4.