Wow the last level was a little confusing for awhile there. I knew you had to drop the star on the cows head but it took me awhile to realise that I had to fly up or down through the little balls on the space rover to control it.
How to win. Place one cactus on a curve and a posion ball at the end of each level. Foolproof method to survive this intense game. Upvote to keep this guide alive!!