Cosmos

Cosmos is a space-based vertical shoot-em-up with very similar play to the Sega/Gremlin game Astro blaster. Waves of alien vessels, comets or missiles appear and try to either ram or shoot you. You can shoot back while moving your ship left and right across the bottom of the screen. An individual wave can be completed by either shooting a certain number of ships, or by surviving a fixed amount of time. There are seven zones in total, each of which have the same order of alien attacking waves, but with increased difficulty due to speed and number of missiles launched by your foes.

In addition to avoiding collisions, you must also watch your fuel which your ship is constantly using. If it runs low, fuel can be replenished by shooting all of the aliens in the current wave, after which you have the opportunity to dock with a refueling vessel. Bonus fuel may also be awarded by shooting capsules during the comet rounds.

Each shot that you make also heats up your weapon. If you don't allow enough time between shots, your blaster becomes too hot, and it will cease to function until it cools down. Finally, you have a warp speed option which will effectively slow down the motion of your opponents for a short period of time. Digitized voices announce when your gun is getting too hot, you are low on fuel, or when your warp mode is about to run out.