Darkspore is unavailable for purchase on Steam and has been for a long time. If you own or manage to find a Origin copy or key of the game however, you can still download and play it through Steam.

Normally, Darkspore was only available for download after you purchased it with a key on Steam. You can still download and play it through it's demo package though. Here's how:

Install it from it's SteamDB[steamdb.info] page or install it directly with the url: {LINK REMOVED}steam://install/102830. This will install Darkspore as if you owned it. It even shows two installation completions once it's done. One for the demo and one for regular Darkspore.



Let the game finish downloading and start it. The launcher should update itself and the game to the latest version.



It should also start patching itself. Afterwards, validate the game just to be safe.



Once this is all done click the "PLAY" button.



You should end up on a login screen. If you haven't yet, add the key to your Origin account.



Login with your Origin account on the login screen and you're now able to play the game through Steam without the need to launch the game through Origin or even have Origin installed.