Experience competitive marble-run engineering with a compact, surface-friendly set designed for head-to-head challenges. This Challenge Edition includes everything needed for two builders or two teams to race: 32 challenge cards that set timed or part-limited goals (longest, fastest, etc.), two rapid-fire launchers, flexible track elements, and nano pads that attach to most smooth vertical surfaces so doors, windows, and cabinets become part of the course. A 16-page illustrated manual walks players through setup and how each element works, then players draw a challenge card and put creativity and problem-solving to the test. The open-ended challenges promote hands-on engineering, iterative design, motor-skill development, and cooperative or competitive play — perfect for solo practice, classroom activities, or game nights. Ages 8+.