Play Liferaft: Zero.
Control the little girls with the ARROW KEYS and jump, grapple and wall jump with "S" ("Z" or "X" are also supported). When near a bell, press the DOWN ARROW KEY to go to the next level. ESC to quit to the level select screen.
Ring the bell on each level to go to the next one. Compete for the fastest time. Try to get the candy and ring the bell to earn bonus levels that can be accessed at the level select screen.
If you're having trouble grappling, you can hold the UP ARROW to cinch the rope and gain altitude on the upswing. Conversely, you can give the rope slack with the DOWN ARROW while grappling to adjust your position or lose momentum. If you're stuck on a certain piece of candy, sometimes it's best to come back later. If you can't get through a level, try watching the video walkthrough for pointers.