Eliminate all viruses by matching capsules of the same color.
The playing field is filled with viruses in three colors: red, yellow, and blue. You control each falling capsule—move it left or right, rotate it, and position it next to viruses or other capsules. When four or more capsule halves or viruses of the same color align vertically or horizontally, they disappear from the board. Your main goal is to beat levels by clearing every virus from the screen. However, if capsules pile up and block the bottle’s narrow neck, it's game over.
Each time you start a new game, you can choose your starting difficulty. The initial level, selected between 0 and 20, sets how many viruses you need to eliminate. Three speed options control how fast capsules drop. Your score depends only on removing viruses, not on your completion time or the number of capsules used. Beating the hardest level lets you keep playing for a higher score, but the virus count stays the same. You earn bonus points for clearing multiple viruses at once, but not for chain reactions—where clearing one group makes another disappear. Faster speeds also boost your points.
