Battle for wesnoth is a turn-based strategy with a bit of RPG.
The game download is over 200 MB, but the game is feature-rich.
The game is quite in-depth, but VERY easy to jump into as a first-timer.
Here are some more features:

Free.
Can be played singleplayer against AI.
Can be played againt other people via internet, LAN & even on the same PC)
Can use integrated Addon downloader for Gameplay Variety.
Built-in Map editor that's easy to use(even for me).

Check it out, it's very fun.

Bump. Also here is some more info:

Description Language: English / French + many many others http://wiki.wesnoth.org/WesnothTranslations
Compatibility with operating systems: As LiberKey, minimal system requirements.
Type of License: GPL (both engine and content)
Author description:

The Battle for Wesnoth is a turn-based strategy game with a fantasy theme.

Build up a great army, gradually turning raw recruits into hardened veterans. In later games, recall your toughest warriors and form a deadly host against whom none can stand! Choose units from a large pool of specialists, and hand-pick a force with the right strengths to fight well on different terrains against all manner of opposition.
Wesnoth has many different sagas waiting to be played out. Fight to regain the throne of Wesnoth, of which you are the legitimate heir... step into the boots of a young officer sent to guard a not-so-sleepy frontier outpost... vanquish a horde of undead warriors unleashed by a foul necromancer, who also happens to have taken your brother hostage... guide a band of elvish survivors in an epic quest to find a new home.

http://wiki.wesnoth.org/Description

Your opinion: Benefits: Would benefit from LiberKey update feature as the game is actively developed. An awesome game that runs on many systems. Its even been ported to the iPhone. Problems: A big download (259 mb) that has alot of files (alot of .png files) when compared to others currently in the LiberKey suite.
A link to the author website: http://www.wesnoth.org/
A link to the download page: http://wiki.wesnoth.org/Download