http://www.ign.com/articles/2014/03/27/dead-space-is-free-on-origin

As of this writing, the original Dead Space is free for download on Origin.

This deal will be available for a limited time, according to Origin, as these specials can "appear or disappear at any time." The On the House program gives away PC games, expansions and downloads for free, without any additional costs. Once downloaded, these games and DLC are permanently available, and not part of an instant game collection.

In IGN’s 2008 Dead Space review, we mentioned the game’s "engaging story" and "atmospheric qualities that will get under your skin and make you jump."