Eat the dots and get bigger. Its not completed so its not that good. The top left corner is your size/mass. If there is no dot, its either on the border or on the variable. This is also Single player. If dot the is not there, than press the green flag again. On the Top right is the amount of pellets you have eaten.
Credit to the actual agar.io game. Music: Chris Poirier - Star Surfing [Tasty Release].mp3 150 views, thanks everyone