There are different themes that can be applied to the game by changing the player name to any of the following:

Theme Name Change Description
"Pocket god" (Pygmy) theme Ooga/Booga/Nooby/Dooby/Klik/Klak Doodler is replaced with a pygmy from the application "Pocket god" and shoots coconuts.
Easter theme Bunny Doodler is dressed as Easter bunny.
"The Creeps" theme Creeps The monsters are replaced with monsters from the application "The Creeps"

Other themes can be accessed by scrolling along the bottom of the main menu. These are:

Theme Description
Holiday theme Doodler is dressed as santa and the monsters are snow themed and it is snowing.
Ghost theme Doodler is dressed as a Ghost. The screen is dark and doodler lights up the area around him.
Jungle theme Doodler is dressed as a Explorer. The background is a jungle and the monsters are all based on jungle creatures.
Space theme Doodler is dressed as an Astronaut. The background is in space and the monsters are space based. there is also a rocket power up
World Cup theme Doodler is dressed as an Footballer. The background is a football pitch and the monsters are footballers from different participating nations.