One strategy for Amazing Alex The Backyard level 2-28, called “Sliders”, is place the elbow in the top-left corner to push the balloon back into the top star after it pushes the skateboard on its way. Most of the level is all set. All that remains is an angled shelf in the bottom-left and two more shelves to complete the path. The objective is to put the skateboard atop the cardboard boxes.
If you have a different strategy for completing this level feel free to leave a comment below.