I wish there is a mode where the snake go toward where my mouse cursor is (similar to agar.io), as opposed to having the controls turn the snake. So in update function where we have the "direction-=.08" and "direction+=.08" bits, "direction" would be assigned a value either due to the pressed state of the 4 arrow keys, or some arctangent of mouse coordinates:

https://github.com/kevinAlbs/SphericalSnake/blob/b907738476d...

Alternatively, keep the current controls, but rotate the whole world to match the snake's direction of movement. Current mix of non-rotating world with rotating controls makes the game more difficult, most snake variants I have played opted for non-rotating world with non-rotating controls (e.g. press right to go right, independent of current snake heading, as opposed to turning clockwise).