I've been playing Battle for Wesnoth on and off for almost a year now and it is more fun every time I play. Each release significantly improves the game, though updating to the latest version almost always requires a full 200+ MB re-download. With this latest release I've been playing almost everyday, and soon convinced my brother to try multiplayer mode with me and it rocks! The game is a little difficult to get the hang of and it rarely gets easier, continuously upping the challenge. Along with all that other greatness of the main game, there is also a large and active fan base that creates new downloadable content on a regular basis.

Oh, and family friendly-wise, a few campaigns have violent artwork in-between battles, there is an occasional mild cursing (as in about once every five hours or so) and of course since it is BATTLE for Wesnoth, you do kill other people and creatures but it isn't very graphic. If the ESRB were to rate it I would predict an E10+ or T.