As we get close to the Natural Selection 2 alpha release, we're switching to distributing all of the updates to the tools and engine through Steam.
If you've already pre-ordered Natural Selection 2, you should be receiving an e-mail shortly with the key that you need to activate NS2 on Steam. If you really can't wait to start downloading through Steam, you can retrieve your key through this web page.
We're not currently selling pre-orders for the game through the Steam store. The only way to get access to the current pre-alpha release is through our pre-order page.
In this release we've activated the server browser, fixed restoring the graphics device when you alt-tab in and out of the game, shored up some visual differences between spot lights in the editor and the game, and added the preliminary documentation on the engine's scripting API. We've also added some additional error checking and compatibility fixes based on the initial feedback from the Engine Test. Please use the "Feedback" tab on the side of the website to let us know of any problems that you have.
If you've already installed the previous release of the Spark SDK and Engine Test, you can uninstall it now so that you don't have two copies taking up space on your hard drive.
Releasing on Steam is another big milestone for us, so we hope you're as excited about it as we are!