Borderlands Has Over 100 Hours Game Time

Mikey Neumann, creative director at Gearbox has said that while the game has a level cap of 50 you can probably beat the game at level 31-35. Also, when you've beaten the game you'll get to play a single player plus version of the game at level 50 to get the best weapons available:

“The level cap is 50, but you beat the game around 31 or 35, somewhere around there. Then you can restart the game and do New Game Plus where everything’s 35 to 50 on the second play-through."

“[There's] more rare enemies, too. The Badasses and the Brutes and stuff like that, which you don’t see as much of in the first. You see them a lot more in the second play through. It’s definitely harder.”

Neumann also commented on play through time of the game revealing there's at least 100 hours game time the first time you play through:

“I just have my own gauge. I’ve maxed out twice, gotten to level 50 twice. It took me about 100 hours. More the second time, actually, and that was to find every single little mission. I wanted to do everything.”

Source: MTV