Richard Garfield played the board game Cosmic Encounter a lot in the 1980s. He loved it so much, he decided to create a card game that had a similar feel to the board game. The result was a little game known as Magic: the Gathering. Perhaps you’ve heard of it?
Magic replaced the alien powers with individual decks, and the chaos of encounters with many different types of cards. Beyond that, there’s not much similarity.
Now Jack Reda, creator and editor of The Warp, a fan site for Cosmic Encounter, has produced an unofficial card game that more closely resembles, without exactly duplicating, the original board game. It looks pretty wild.