Levers, pulleys, and wheels—they’re tools that outline some of the most foundational principles in physics. But foundational principles are boring. What’s fun is using a lever to catapult a boulder at a castle, breaking down the bricks one by one to discover a dragon sleeping inside.

That is the premise of Simple Machines, the latest iOS app by the educational game studio Tinybop. In the past, Tinybop has made interactive books on the human body and plant life. They’ve created a fun simulator for kids to build their own robots. But with Simple Machines, they’re taking aim at a very particular part of student curriculum: The first stages of STEM (science, technology, engineering, and math), in which kids commonly learn about six “simple machines”—the lever, pulley, wheel, wedge, inclined plane, and screw.

READ MORE: STEM Curriculum Turned Into An Addictive Game | Co.Design | business + design.