Players can select the degree of starting difficulty any time a new game is started. The initial level chosen is a value between zero and twenty that determines the number of viruses to clear, and the three game speed options change how fast the capsules fall in the bottle. The player's score is based solely on the elimination of viruses, not on the time taken to complete the level or the number of capsules used. If players complete the highest difficulty level, they can continue playing to accumulate a higher score, but the number of viruses to clear remains the same. Additional points are awarded when multiple viruses are eliminated at once, but no additional points are awarded for initiating chain reactions, in which the elimination of one set of objects triggers the elimination of another set. The game speed is also a factor in how the game calculates scoring; higher speed levels yield more points.