Summer has now truly begun, with the launch of Killing Floor's latest seasonal event. The free Summer Sideshow: Pier of Pain update introduces another map of steampunk carnival carnage, Steamland, which is the first of Tripwire's new Objective Mode maps. Oh, and the survival shooter is free for everyone to play until July 11. Come, join the festivities!

Objective Mode introduces, as you've probably guessed, objectives, allowing for maps more complex than simply "kill all the monsters and don't die". Pier of Pain will have you repairing power boxes to open the fairground's gates, escorting Ringmaster Lockheart, and more. Also, as you'd hope, it's filled with little carnival games to play on the side.

Earning all the Summer Sideshow achievements will unlock new character Steampunk Mrs. Foster.

Tripwire's also selling a new DLC pack of four steampunk weapons made by the community, including a steam musket and absurd shotgun. It'll usually cost $7.99, but has launched at $3.99 because hey, Killing Floor and all its DLC are on sale for the event.

Check the Summer Sideshow site for more, and run on over to Steam to start playing while it's free. You can buy Killing Floor to keep for only $3.99 (80% off!) if you take a shine to it, which you may well: it is jolly nice.