Absolute steal for this piece of 4X Sci-Fi gaming history. Spiritual successor to the Civ series. Rated 9.5/10 on IGN.
Sid Meier's Alpha Centauri™ Planetary Pack includes the original Alpha Centauri and the expansion, Alien Crossfire.
Mankind begins its most monumental task – the colonization of space. A crew of internationally renowned scientists and security strategists, with wide-ranging convictions and diverse ethics, embarks on a mission that will change the world. One Planet. Seven unique factions. Which will you lead? Each faction has its own agenda, each leader a final goal. You must play to each strength and exploit each hidden weakness in your quest to rule the future.
I've only played Civ 5 and Civ 6 (love them both) and had fun with Beyond Earth - has this game aged well? I suppose for $2 its worth a try.