Arguably one of the best (if not the best) Flash game series of its kind, Dr3i is more than just a game of avoidance. As before, collecting small positive and negative signs speeds up and slows down the rotation of the obstacles that you must make your way past. However, this 3rd version in the series introduces an animated "beast", an engaging cloud of black smoke that follows you in pursuit.
The beast is also affected by the positive and negative signs. Positive signs will make the beast grow larger and faster, negative signs will reduce the size of the beast and make it move slower. A smaller and slower beast is essential if you wish to finish this game.