Portal 2: Peer Review

Developed by Valve
Release date: 04 Oct 2011
PuzzleAdventure
Portal 2: Peer Review
Developer: Publisher: Valve
Themes: Comedy
Player perspective: First person
Game modes: Single player
Portal 2: Peer Review includes an additional course for Portal 2 co-op campaign, dubbed "Art Therapy"; as well as Challenge Mode for both single-player or multiplayer campaign, where players can play specific levels and compete in friends/worldwide leader-board.