Cartoon Network's Emmy Award-winning animated series makes its DS debut with Imagination Invaders. Inspired by season four's episode "Make Believe It or Not," players guide prankster Blooregard Q. Kazoo on an adventure to save Madame Foster from the Space Nut Boogies. This involves exploring the Foster's house, room by room, to complete quests on behalf of Cheese, Imaginary Man, Jackie Khones, and other characters. As players travel through the residence, they must slink past patrolling guards and other dangers. Disguises can be worn to help avoid detection, while spit wads are used to disable cameras, solve puzzles, and distract nearby enemies.
The player controls Bloo using the buttons on the Nintendo DS console. Bloo can jump and fire spit wad from a straw. The main objective of the game is to rescue Madame Foster who has been kidnapped by Space Nut Boogies. To do this the player must earn the cooperation of different characters from the television series by performing tasks for them in order to gain their help. Throughout the game player must also find eggs laid by Coco which contain Coco cards. Coco cards allow players to view pictures they collect in their scrap book, which can be viewed from the pause screen.