Critics often contrast it with the original to highlight its shift in focus.
: The separate co-op campaign isn't just a side mode; it features unique puzzles that require two people to think with four portals simultaneously to solve. Critical Perspectives ABOUT Portal 2
: The game expertly introduces new mechanics—like propulsion , repulsion , and conversion gels —gradually enough to avoid frustration but frequently enough to keep the gameplay fresh. Critics often contrast it with the original to