In Dotz, you are a circle with a mouth and what do you want to cram into this mouth? Dots, of course. Your circle is surrounded by what must be a razor-sharp dashed-line perimeter. If you can touch another circle with this perimeter, you will kill your enemy and gain a huge point boost. However, if your circle gets touched by another perimeter, you yourself will give up the ghost. As you gain levels, your circle expands to meet the perimeter. As soon as you level up, you shrink back down to a safer size.
Use mouse or arrow keys to move. Space bar or left click gives you a temporary speed boost. You will die if your circle gets touched, but you can kill with your dashed-line perimeter.
When your circle is in a level of dangerously large expansion, stay in defensive mode - hang out in the periphery and focus on gobbling dots. After leveling up, go on the attack and take out some smaller circles! Use the dash button to escape persistent foes.