Portal 2 Perpetual Testing InitiativePortal 2 fans can now create co-operative maps (called “test chambers”) and share them with the Steam community, thanks to a free update for the game’s puzzle maker, publisher Valve today announced.

Valve says over 170,000 single-player test chambers have been made using the in-game editor, called the Perpetual Testing Initiave, since Portal 2’s release on the PC and Mac last May. But this is the first time the community will be able to create puzzles that requires two players.

The free update also introduces a new “Quick Play” feature that allows players to quickly access top-rated maps.

To entice gamers into trying the new content, Valve is offering current Portal 2 owners a 75 percent off coupon on digital distribution service Steam to give away to other Steam users.