5 addicting open source games

There are lots of games in the world of open source, which means lots of cheap fun. Well, sort of. Many of these games aren’t complete enough to be playable, others have been abandoned, and some just aren’t very fun. But there are many good open source games, and out of these a few are just amazing. So amazing, in fact, that you just might get addicted.
I’m pretty new to open source games, but here are 5 of those rare, addiction-inducing open source games that I’ve found, in no particular order. All of these games are available for Windows, Linux, and MacOSX. Fun for everyone!