mini: avoided a double-definition, safes 5 bytes
mini: the function redraw_screen() is only used once, so write it directly - safes 9 bytes
mini: the function drop_food() is used 2 times, but we hardcode the initial position and so we can write the true random drop_food() after each snake_feeding - safes 3 bytes
mini: using the builtin 'alias', we can abbreviate 2 commands - safes 26 bytes