Use the left / right arrow keys to control your Droplet. Try and collect as many hearts as you can as you fall! Look out for the tea and joysticks for extra health and points. If you land don't stay still for long - it rapidly reduces your health. Press Up to jump.
If you're interested you can read about the development of this game (and what the Droplets are!) here: http://www.photonstorm.co m/games/droplet