'Tony Hawk's Pro Skater HD' from Activision.
Activision's Tony Hawk's Pro Skater HD is now available on Valve's PC game digital distribution service, Steam, for $9.99 USD. The game takes elements of the classic THPS games and gives them a fresh update to create an all new skateboarding experience on the PC.
The PC version of this game (which is also available for Xbox 360 via XBLA) has no online or offline multiplayer play, but Activision points out that it has endless replayability with four single player modes and the addition of "PROJectives" (brand new objectives for those that complete the traditional ones).
The THPSHD PC game will also be receiving downloadable content in the near future. Call the "Tony Hawk's Pro Skater 3 HD Revert Pack", the DLC will include three levels from THPS3, the Revert move, new pro skaters, and more. The DLC will be priced at $4.99 USD.