Gratuitous Space Battles - Valve
Updates to Gratuitous Space Battles have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Gratuitous Space Battles
  • Bug Fix: Limpet launcher UI no longer shows it tracking targets and firing if all mines are currently launched.
  • Bug Fix: Limpet launchers no longer draw if cloaked.
  • Usability: Ship icons on the deployment screen now list their speed and cost in the mouseover tooltips.
  • Usability: The post challenge button greys out once you have actually submitted the challenge
  • New Feature: New option after a challenge victory to retaliate with the fleet you just won with.
  • Usability: The 'go to fleet hq' button isn't an option any more for the outcome window during challenges, when you don't earn honor anyway.
  • Bug Fix: Fixed bug where some fighters, depending on speed, may not be able to dock with a carrier.
  • New Feature: New 'challenge details' screen, complete with retaliation list and image previews.
  • New Feature: 'stick together' order for fighters, keeps them clustered in squadrons.
  • Bug Fix: Intel GMA 450 video cards now correctly default to software processing and don't crash on startup
  • Bug Fix: The ship design screen now correctly calculates armor resistance, which was previously wrong!
Serious Sam HD: The First Encounter - Valve
A free demo of Serious Sam HD: The First Encounter is now available on Steam.

Grab the demo and go back in time *IN HD* as the legendary Sam 'Serious,' where you'll head to ancient Egypt to battle the overwhelming forces of Notorious Mental and the Sirian army.
Borderlands Game of the Year - Valve
Borderlands and the Four Pack are 50% off until Monday, 10 AM PDT. Lock, Load, & Face the Madness!
Alpha Protocolâ„¢ - Valve
Alpha Protocol™, the upcoming Covert Ops RPG from SEGA and Obsidian Entertainment™, is now available for pre-purchase on Steam. Pick up the game before its release and receive a free copy of Space Siege.

Already own Space Siege? Pre-purchase now and you can gift your extra copy to a friend.
Global Agenda: Free Agent - Valve
Updates to Global Agenda have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Global Agenda
  • Made changes to Character Creation and Character Selection screens to improve network resiliency
  • Mercenary PvP queue will now not be enabled until you reach Level 8. Between Levels 5 and 8, players can earn experience and credits playing Low and Medium PvE missions
  • The matching system for Mercenary PvP has been modified to lessen the likelihood of playing with players outside your general level range
Sol Survivor - Valve
Updates to Sol Survivor have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Bugs fixed:
  • Fixed crash bug when attempting to upgrade silos.
  • Fixed rendering artifacts from forced driver MSAA on NVIDIA cards.
  • Fixed invisible terrain on Shader Model 2.0 hardware.
  • Fixed text chat on international keyboards.
  • Fixed unsupported hardware crashing instead of displaying a message window.
  • Fixed survival balance causing bosses to come in too early.
  • Fixed prebuilt turrets not counting in player records, blocking Equal Opportunity Constructor.
  • Added fallback music engine for systems that do not have Windows Media Player.
Enhancements:
  • Added Co-Op Campaign multiplayer mode.
  • Added promotion message archive, viewable by clicking rank on main menu.
  • Tweaked radiation and railgun turret damage.
  • Tweaked difficulty on some Versus and Co-Op maps.
Mount & Blade: Warband - Valve
Mount & Blade: Warband is the eagerly anticipated stand alone expansion pack for the game that brought medieval battlefields to life with its realistic mounted combat and detailed fighting system. Lead your men into battle, expand your realm, and claim the ultimate prize: the throne of Calradia!
Eufloria - Valve
Updates to Eufloria have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Eufloria
  • Fixed a bug in the pathfinding of 2.03
  • Added drawing from Lua script
Shatter - Valve
Updates to Shatter have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Shatter
  • Added steam cloud support for all in-game progress
  • Fixed a bug where following a link to a web page from a popup within the game would make all other in-game popups attempt to take the user to the same web page
  • Updated the readme to include additional known issues
  • Fixed a crash that would occur when detecting certain input devices. A warning is now shown when Shatter detects an incompatible device
  • Fixed an issue with leader board times for boss rush where times over 40 minutes would wrap back around to zero
  • Added detection of modified game data. When the user has local modifications to their data Shatter will enter offline mode and will not upload scores
  • Fixed an issue where Shatter would incorrectly enter offline mode if the user had set their Steam account to appear offline. Shatter will now enter offline mode if Steam is offline
Total War: EMPIRE – Definitive Edition - Valve
Update 1.6 for the award winning Empire: Total War is available today. The update introduces a large number of revisions to the Artificial Intelligence in real time battles. Amongst many other improvements, the Battle A.I. now maintains its lines more rigorously, has better army movement and engages in melee more tactically. It is also better at protecting its own advance and engaging opponents with flanking attacks.
...