use the hammer when you have 2 of the same above the pet to put 1 on the right hand side, then move.

Sorry, no tips. I'm having the same problem. We need a key, but the 5 levels to play to get the key are purple and unplayable. Anyone else?

I am not able to move the pet from the left side to the right side in this level it would be great if somebody has a tip for me on that problem. Thanks.