From NASA's site for kids:
you can take an imaginary trip to a black hole right now!
You will also visit such interesting places as a giant array of radio telescopes in the New Mexico desert and NASA's Jet Propulsion Laboratory in Pasadena, California. Then you will blast into space and visit the Earth-orbiting Japanese VSOP Radio Telescope (launched in 1997) and Russia's RadioAstron telescope (not yet launched).
Then you will leave Earth orbit and go on to explore other galaxies, an interstellar gas cloud, a neutron star, and finally, a black hole! You will earn "Antigravity Tokens" along the way, so that you will be able to escape from the black hole's tremendous gravitational force.
Object of the game:
Be the first to reach the Black Hole armed with at least 25 Antigravity Tokens so that you will be able to get yourself out and go home after you are through exploring.
Game available at - http://spaceplace.nasa.gov/en/kids/svlbi_do1.shtml