Warzone 2100 is an in development RTS (Real Time Strategy) game, based after "The Collapse," a nuclear war that obliterated most of the population. You play as The Project, a group trying to rebuild humanity, but who is hampered by various enemies.
This is going to be a short review, because I haven't played the game much yet, but it'll be close enough.
The biggest gameplay difference is that you get to design your own vehicles. In fact, you need to design vehicles, or you only get a bunch of trucks, the basic building unit. There is also a huge tech tree, which allows for nearly infinite possibilities in design and construction. Some different construction options are: wheels, half-tracks, treads, and VTOL. There are a huge number of weapon types, including: rockets, machine guns, mortars, and AA guns. There are the campaign, offline skirmish, and online multiplayer modes. The offline skirmish and multiplayer have everything unlocked, not relating to the campaign, so if you want to just start playing, you can. The campaign is designed around time-sensitive missions, so you need to act fast, and think faster when playing through it. There are very few things unlocked at the beginning of the campaign, and your research is very limited.
I haven't really played this enough to give a truly complete review, but I hope this at least gives you some idea of the game.
Pros: Designable vehicles and interesting storyline.
Cons: It's still Alpha, so there are some bugs. The storyline is rather non-essential to gameplay, so much so, that the intro movie is an option on the main menu, instead of integrated at the beginning of a new campaign.
Overall: An excellent game for those who like RTS with an interesting, if unimportant storyline. The designable vehicles are definitely a plus, but it's a little confusing unless you look at the website guide first.