"spela inte" is not correct?
No, you'd spela a game or a sport. So unless you do mean don't play a game with your food, it is incorrect.
Like oreo and marshmallow checkers...or chess.
Could you say use "ej" instead of inte? How would they differ?
Yes, you could. Generally speaking, ej is the much more formal version of inte. I don't recommend using it in any normal context.