In "Bad Piggies HD," players help the mischievous green pigs from Angry Birds achieve flight using a variety of contraptions. The goal is to navigate through different levels, collecting stars and reaching the end point. With a mix of physics-based puzzles and creative building, players must use their problem-solving skills to create unique and functional machines. This engaging and challenging game allows players to experience the thrill of seeing pigs soar through the sky.