The Art is great and I love the different backgrounds for every age.
The only thing I would change is to make sure the enemies spawn outside of the screen. Sometimes they spawn almost inside the player character which makes dodging them almost impossible.
I think the input handling could use a little bit more work though.
You could use a queue of inputs so that no button press is lost. Right now only the last input is considered every step which makes multiple turns in quick succession quite difficult. It is also possible to make a 180 degree turn right now by pressing two buttons between two frames.
For example if you're moving down and then press left and up before the next movement you loose if the snake is 2 blocks or longer.
I personally dislike the use of different scale of pixels in the sprites, also known as "mixels", which gives the different assets an inconsistent look. For example the carrots have a much higher resolution than the cars.
The gameplay is really fun and the additional mechanics work really well.
