http://www.rpgamer.com/news/Q3-2011/071511b.html
The main story should take around 30 hours to complete, but you are free to explore the island as you want. Even though there is a story coming into the island, there are no time constraints on you, so you are free to explore, scavenge, and take on as many side quests as you want.This is an open world game with different beats and you are free to set your own pace. When you are exploring, taking quests, or crafting weapons the game takes on a slower pace, but when in combat and with your friends the game takes on a faster, action-oriented pace. Kummer said the action never really takes a backseat to the story, rather how and when you choose to engage the story is up to you. If you stay on the main path, the story and action will stay consistently fast-paced. Kummer was also asked how he felt about being compared to Borderlands by a lot of media outlets. Kummer admits that the comparisons to Borderlands and games like it are apt but only in terms of the action. He said the key difference is that Borderlands is not as story driven and doesn't have the emotional impact and slower beats of Dead Island.