PySpaceWar Two ships duel in a gravity field. Gravity doesn't affect the ships themselves (which have spanking new anti-gravity devices), but it affects missiles launced by the ships. You can play against the computer, or two players can play with one keyboard. There is also a Gravity Wars mode, where the two ships do not move, and the players repeatedly specify the direction and velocity of their missiles. WWW: https://mg.pov.lt/pyspacewar/