Superpose, observe, collapse.
The path home lies deep within infinite worldlines.

After completing a mission, engineer Ket Everett is en route home - until her crashing onto a frozen world in the distant future.

Before her stands a mega-structure: a quantum gateway, the Tower. And her only chance of escape is to restore it.

Guided by mysterious data transmitted from the future, Ket must unlock the true power of quantum computation - and, among infinite possibilities, search for the one solution that could overturn her fate.

Design. Repair. Test.

Confront damaged quantum gateway by applying logic and reasoning. Arrange quantum gates with distinct behaviors to build original circuits and solve each puzzle in your own way.

Your First Quantum Algorithm

Start with basic binary logic and quantum gates, then gradually explore quantum states, superposition, and phase operations. Build a solid foundation and discover the true nature of quantum computation.

Rewrite Worldlines, Change the Future

When quantum computation becomes powerful enough to predict the future, Kate realizes that her future self may have made different choices. Faced with diverging worldlines—what decision will you make?

Cassette Punk and Post-Apocalyptic Ruins

Put on your helmet and explore a towering structure of ice and concrete, from superposition generators to quantum memory vaults. If future civilizations once existed here, what happened to them—and what is the truth behind the Tower?

Sandbox Mode, QASM Support, and More

Freely build and test circuits in sandbox mode. Import and export QASM code to create your own quantum experiments and turn the game into a personal quantum simulation lab.