Gamexplain.com says, "When the original (and awesome) Dead Island trailer hit the internet a few months back, jaws hit the floor. Its memento-inspired reverse of time mechanic was poetic, and best yet, it featured zombies! While details were scarce, we knew it was going to be a cooperative zombie-killing FPS. This, of course, lead me to believe it would be very similar to Left 4 Dead. After getting some hands-on time with the game, I can say that while the game has some similarities to Valve’s game, there are some noticeable differences:"