It's a snake eat snake world in SuperSnake.io. Unless, of course, the snake in question ate a green power-up, then they can't be eaten for five seconds. But that won't keep them safe forever, will it? When the opportunity once again arises, you'll be there to swallow them up. There are other power-ups, too. Learning to utilize them all will make you the king-snake.
Steer the snake with your mouse, and use the five power-ups:
Red - Levels You Up
Green - Gives you 5-seconds of invincibility
Blue - gives you a 5-second speed-boost
Pink - gives you spit charges. Use the mouse button or w to spit.
Golden - Super snake
Learning to use the power-ups is about the only strategy you need. Don't bother eating the green ones unless you're in danger of being eaten yourself. Or, if you want to set up an attack, eat the green power-ups to try to deny them from your prey.