Firstly I have to say I really like how you type to code in, and also how you included a settings menu (and one that didn't just effect music and sound, but also the speed of the snake, very nice addition and one that could have been left behind in a game jam)
I, like many people got stuck on three
Until I didn't! With the power of brute force!
I then just got stuck on level 4 right after
In a game jam it is usually best to include some level skipping mechanic so if they get stuck they can still play the rest of the game
Good luck in the jam!