Your player (blue) will always go slowly towards your mouse. Eat the tiny dots (food) to get bigger, and if you're bigger than one of the guys, try to eat him! Don't let a guy bigger than you touch you though! Exact masses are shown at the top of the screen. Eat by touching the food. Tip: if the red eats the black or vice versa, then you're pretty much done for unless you're a hardcore player or you have a lot of time. Tip #2: You get slower as you get bigger.
This is just a recreation of Agario, a blob-eat-blob massively multiplayer game. I couldn't make it massively multiplayer, so I made it with AI. Good luck! Real Agario: agar.io (copy and paste the link)
