Browse every challenge across all four categories. Filter by type, difficulty or time — and start playing in one click.
Test your knowledge of stellar types, the Hertzsprung–Russell diagram and stellar lifecycles.
From event horizons to Hawking radiation — how much do you know about the universe's strangest objects?
The Cosmic Microwave Background, inflation theory, and the fate of the universe.
Planets, moons, dwarf planets and everything orbiting our Sun.
Calculate transfer orbits and match spacecraft to their correct trajectories using logic.
Time dilation, distance calculations and relativistic speed puzzles that challenge real physics intuition.
Match stars to form the correct constellations. Spatial pattern recognition with a stargazing twist.
Lateral thinking puzzles inspired by Einstein's thought experiments. See past the obvious.
Multi-step logic problems that explore the great silence of the universe. Deeply satisfying to crack.
Gentle riddles about lunar phases, tides and Earth-Moon dynamics. Perfect for beginners.
React fast to navigate your spacecraft through a debris field. Trains reflexes and spatial awareness.
Decode alien transmissions into readable text. Pattern matching under time pressure.