Enter these on the pause menu:

Big Head Mode: up,down,down,up,right,right,left,right
Infinite Health: U,R,D,U,L,D,R,L
Inf. Scrap: D,D,L,U,U,R,U,D
One hit kills enemies: D,L,U,D,D,L,R,R

In the movie,when you see Rodney talking to the hip-hop robot,look to the left of the crowd after
Rodney leaves.You should see a Sid-from Ice Age-robot!