Every time you make the correct pattern, the game becomes difficult. The game starts easily when you have only two or three changes to make. Required changes start to increase as you progress through the game. And the real fun begins when the small grid which you observe starts to rotate.
Child
Impos
Match
Steve
Metal
Sling
Bubbl
Off T
Elect
Airpl
Color
Play
Unico
Dora
Reach
Cat A
Golem
War T
Ballo
Save
Foot
Woodt
Amgel
Hero
Bubbl
Cross
Hoov
Loop
Colle
Voodo
Block
Princ
Landm