Take a trip to space and explore the atmosphere in the world’s only space elevator.

Become an evolutionary detective to find the Mystery Animal! The animal kingdom (Metazoa, in Greek) is full of our distant relatives… some more distant than others! Metazooa is a game that tests how well you know our extended family tree.

Your goal is to figure out today’s Mystery Animal in as few guesses as possible. Wrong guesses will narrow down the answer by taxonomic rank (kingdom, phylum, class, order, etc.) The more your guess has in common with the answer, the more you will learn about the Animal.

Detective Wiki is a discovery game that challenges your knowledge of the world through endless questions about ideas, people, places, and things.

The Largest Collection of Interactive Geometric Puzzles

120 Levels: From Very Easy to Really Hard, 11 Tutorials, 10 Innovative Tools, Automatic Verification of Solutions, “Explore” Mode and Hints, Dynamic Geometry in Action

Chronophoto is an online history game that challenges players to guess the precise year a historical photograph was taken by analyzing visual clues and context.

Online roguelike with sci-fi. Asterogue is an open-world, real-time roguelike space trading and combat game where players explore a procedurally generated galaxy, trade goods, and engage in tactical space battles.