15 Single Player Games That Stunned Gamers

PORTAL

Every time Valve makes something, you sit up and take notice, but when Portal launched back in the day, very few expected it to be what it turned out to be. Did we think it would be good? Well, yeah, it was Valve, for goodness’ sake. But did we expect that this small, experimental puzzle game would legitimately be one of Valve’s best ever games, going on to spawn the even better Portal 2? Absolutely not.