Fantasy: How Can I Become an Immortal Just by Building a Playground?

[The farming system is humorous and easy to traverse] Once Zhang Xuan traveled through time, he became a useless young man in the capital who was shouted at by everyone. Don't panic, your playground system is activated! [Ding, your pig pen has been transformed into a piggy claw machine! Your haunted house is built successfully! Your jumping machine is successfully built! From then on, Zhang Xuan became famous in the capital, with dignitaries flocking in an endless stream, and ladies calling him Xiao Xuanxuan secretly. Until a certain terrifying demon arrived and was about to destroy the capital with one strike. Boom! The jumping machine rises from the ground and beats the devil to pieces with a clang. The people kneel down and worship, calling them immortals! Zhang Xuan was helpless, I just built a playground, how could I become an immortal?