A free update to Portal 2’s Perpetual Testing Initiative has given players the ability to create co-op test chambers for Valve’s popular puzzle-platformer.

Prior to the update, only single-player levels—which now number more than 170,000—could be created.

The update also introduces a "Quick Play" feature, which allows players to rapidly access the top-rated maps in various categories.

To help players find a co-op partner, Valve is giving every current owner of Portal 2 a Steam coupon for 75% off a copy of Portal 2, which can be given away to other Steam users.

The update is live right now, and can be applied via Valve's Steam service.