Valve implemented and tested a new competitive multiplayer mode for Portal 2, but scrapped it after it became apparent it simply didn't work, Valve writer Erik Wolpaw has told 1UP.
"Along with co-op, [we had] the idea of sort of a competitive Portal multiplayer," explained Wolpaw. "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."
The mode would see players moving a ball from one end of a game space to the other using portals, with the opposition's goal to prevent this from happening.
However, Wolpaw added: "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. 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 is scheduled for release on February 9, 2010 for PC, Mac, Xbox 360 and PS3.