The competitive multiplayer aspect was a "hot mess."
Valve Software writer Erik Wolpaw revealed that Portal 2 almost had a competitive multiplayer component, however it was removed after early tests. The news came during 1UP's visit to the developer during its 1UP Cross Country Game Tour.
"Along with co-op, [we had] the idea of sort of a competitive Portal multiplayer," he said. "We went down that path, actually, for a little while and had something up and running--the best way to describe it is sort of speedball meets Portal. You know, a sports analog."
Called "spite-your-neighbor," the multiplayer mode involved moving a ball from one end of a space to the other using portals. Competitors would attempt to stop the player by using portals as well--an example described trapping the player with a portal shot onto the ground.
"It quickly became apparent that while it's fun for about two seconds to drop portals under people and things like that, it quickly just devolves into pure chaos," he admitted. "It lost a lot of the stuff that was really entertaining about Portal, which was puzzle-solving. Cooperative puzzle-solving was just a much more rewarding path."
Portal 2 will "ship" with a longer campaign than what was experienced with the original Portal. The sequel will also provide players with a cooperative multiplayer experience when it launches in February 2011.