Hyperbola

Hyperbola is a game inspired by perhaps the greatest arcade game of the golden period of arcade games: Defender!

The aim of the game is to defend the astronauts found on the surface of the planet from the marauding aliens. Alien landers will try to grab the astronauts and drag them into space, thus turning them into hyperactive mutants. If an astronaut is grabbed, you must shoot the alien lander and catch the falling astronaut - if the're too high up to land safely back on the planet - all while dodging the variety of alien life-forms which are zooming around.

Once you completely clear out each wave of aliens, another wave will materialise. Be warned, if all astronauts are lost, the planet will explode and all remaining aliens will become mutants. You must then destroy all of these before a new planet with new astronauts becomes available to you.