Global Offensive adds general updated features to Counter Strike as well as old favourite game modes and two new game modes called Arms Race and Demolition which are referred to as Arsenal mode. The updated features include support for matchmaking, leaderboards, and an Elo rating system which will be used for calculating the relative skill level of players in two-player games.
It is also worth noting it is one of the few console games which will feature keyboard and mouse support!
The game is due to be released tomorrow on the PS store, Xbox Live and Steam and is still available for pre-order now. In fact if you pre-order on the steam store now you will get a 10% reduction to enjoy!