Death March kara Hajimaru Isekai Kyousoukyoku

From Yen Press: Suzuki is a programmer in the midst of a death march-crunch time, when coders live on caffeine and pull twenty-hour days. He just needs a little nap but then he has a dream. A dream where he's in another world, with RPG powers right out of his game. A dream where he calls down a great disaster. A dream that, suspiciously, just won't end. Official Japanese