Looks like Electronic Arts is in a giving mood, as Dead Space is now available for free on Origin. You can find the game here, and according to the official listing the offer will be available until May the 8th. Of course downloading the game will require Origin
https://www.origin.com/en-ie/store/buy/dead-space/pc-download/base-game/standard-edition-ANW.html
https://www.origin.com/en-ie/store/buy/dead-space/pc-download/base-game/standard-edition-ANW.html