4.0
The game is shifting of blocks which acts as holes where you drop kittens into.
The blocks cannot move in a direction if there are kittens of other colors blocking it.
By itself, it has quite abit of thinking needed to complete each puzzle.
However, they added a time limit.
So the game difficulty mainly comes from the time limit than the complexity of the puzzle.
For me this kinda spoils the fun a little.
But else, it is cute and excluding the time limit, is an interesting puzzle solving concept.