Nice idea. Bit of feedback would be good when the rain this the ground like screen shake.

The snake controls caught me off guard. It would have been better if the player was frozen in the beginning waiting for a key press. I also didn't understand the role of the acid until I realized that it can't hit the bottom. 

The acid sprites aren't all that visible when they are on a green background.

The absence of sound effects was unfortunate.  Music could use some variety. Currently it also loops in an odd way.

I really like the curved movement of the snake, compared to the well-known rectilinear snake. The game could use some sound effects no notify the player of good events (eating) and bad events (acid rain). Also, don't call the player a loser when the game ends :-(

The movement of the snake feels great and I love these kinds of games. I’d suggest a couple improvements.

• What’s the incentive for eating and growing? I was expecting some kind of score boost somewhere.
• Don’t start the snake movement automatically, wait for some keypress.
• When the snake’s head hits the wall, have it slide OR stop the “body” from “following” so it maintains its shape. Otherwise it’s quite easy to cheese the game by just curling in a corner.

First this game adapt with theme very well. Who will think acid rain and snake can be merge? lol

Concept quite simple but powerful in term of gameplay.

For audio I don't hear anything.

Art can be develop to be more snake or cuter.