Space Battle is a power struggle between you and your opponents for control of the galaxy. This is a "take that" card game with silly cards.
There are two similar versions of the game in the box.
Everyone starts with some ship cards randomly drawn from the ship deck. Each ship gives you access to use particular kinds of weapon cards that you draw from a shared deck. These cards like "red laser" and "drones" are used to wear down other ships. Some cards destroy ships in ways outside of weaponry.
When you destroy another ship you get the printed Victory Points for it. If all your ships are destroyed you go to the deck to see if you are lucky enough to get a card that gives you another ship to stay in the game, otherwise you are eliminated from play, but victory (in one version of the game is based on points).