Interesting idea, but the gameplay is pretty numb. The game is about timing, but you know when to react. It would be better that the tail would turn red randomly.  Also it would be good that the snake would change direction, because I bet people will be sick/dizzy while playing this for a longer time.  At least I started to get dizzy and had to stop playing, Sorry. With some minor changes it could be a fun game :)

Interesting gameplay. 

Nice Job

I stopped half the way around the planet. It felt too repetitive at some point, but interesting idea, good job

Cool concept, but very hard to time it right about halfway! It feels like you have to wait a bit long for the light when the snake is very long. Very thorough tutorial, and unique graphics!