Ovar.io is a very unique and interesting io game. The characters you can play are different classes of sperm. Nuff said.
To play, simply guide your fleet of sperm around the map with your cursor, and kill other sperm in your path. Scattered around the map are plenty of power-ups to help you on your journey.
The strategy is to simply avoid the sperm classes that over-power yours, and capture as many ovaries as you can.