The Steam Summer Sale just kicked off and as per usual there is a bunch of PC, Mac and Linux games up for sale at, in some cases at least, heavily discounted prices. This summer's biggest PC sale has a sci-fi theme and as is the norm these days there are a bunch of incentives designed to draw you in and relieve you of some of your hard-earned cash. You've got until July 5 to take advantage of the temporarily reduced price list, so if you've had one eye on a certain game for a while now it's time to check your wishlist and see if you can be tempted by the new-look pricetag.