And not doing much is a problem. You can walk, but there's only two small rooms for you to go. You can't interact, you can't analyze, you can just see and wait the time to ran out to the next scene.
Story wise, there is no why nor how; things just happen. I know it's supposed for you to piece it together, with sounds and whatnot, but the story is so haphazardly put together that, in the end, you can't do squat instead of feeling numb of such blandness.
Also, why a chainsaw? A lot of instruments, even construction tools that people normally have on the house would set the end well. Hell, he could've use blunt objects sounds on the body to seem like he's breaking bones to help hacking and sawing the victim; even put some muffled screams to seem like the person is being sawed off alive, but nope! "Chainsaw is scary, ooga, booga", bullcrap!
Thank heavens that it's free, or else a lot of people would refund the game.
Postscriptum: Sorry if it sounds mean or irate, but it sounded so good, just to be a cop out in the end.