Slipstream is a free racing vehicle simulator trying to be physically accurate and fun to play at the same time! Contrary to most simulators out there it's not designed around a single type of vehicle. It should be able to support anything from a bicycle to a car or anything else that can be driven around on a racetrack for that matter.
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Wazzal (dx8 game)
Wazzal is a single-player role-playing space trading and combat game that features a compact plot, ship-boarding mini-fights and allows to switch control between ships during team battles. The recently open sourced game was made by Ville Mönkkönen of Instant Kingdom (IK). He is responsible for excellent freeware games including Notrium and is currently working on a for-pay top-down fantasy RPG.
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Xonotic
Xonotic 0.5 brings new maps, vehicles and multi-language support. Many more details can be found in their annoucnement post.
