Bad Piggies Rise and Swine Level 2-20 can be 3-starred in two steps. Build a three frame motorized cart with the grappling hook above the first frame. Use the plunger to lift it up on the platform above. To beat the time trial, place the grappling hook on the middle frame. Guide your contraption all the way to the other end, and carefully send the plunger on the cliff to pull it up to the finish.
If you have a different strategy for completing this level feel free to leave a comment below.
To get the star, tried the video method many times and the vehicle always stalled halfway up the hill. Tried moving the grappling hook to the middle section and got it first time. So either I was just not doing it right with the walkthrough strat, or it’s changed with an update.
Like the above, as of 2016, I had to move the pig too the back box and plunger to middle in order to get the star box.