The third level is the D Level. This level works similar to the whack-a-mole games. As you go through the level, you'll encounter three slots of holes. In it, a letter will sometimes appear and a Pokémon will come out. Hit the button and it'll go back in. The Pokémon captured here don't get added to your Pokédex

Bronze Medal Requirements:
Pass a level getting the Pokémon correct

Silver Medal Requirements:
Successfully capture 20 Pokémon

Gold Medal Requirements:
Capture every Pokémon without making a mistake