Have you ever saved someone's life? People who have say it's one of the most powerful emotional experiences you can have. And Lifesaver give you a sense of what it feels like. Lifesaver throws you into three films where someone will be dead in ten minutes unless you do the right thing. In films one and three, the victim's had a heart attack; if you're on a mobile device, you move your device up and down, two times a second, to do CPR on them. In film two, someone's choking - you move your device sharply to do the Heimlich Manoeuvre. If you're on a regular computer, you can do all this with key presses. You have to successfully complete films one and two to get to film three. The plot varies according to what you do: get it wrong, and someone will die; get it right, and sense the thrill of saving a life.