Sorry, but even if the alternatives you offer do not belong to your "fun" definition, they are sweeter alternatives. Fruit, yoghurt, weetbix, breadstick have all the common taste factor.
The more you keep this, the less he will eat real food, and will only want snacks,
Have the meals together as a family, have him seated in his high chair, while you eat the same meal, offer the plate, and if he refuses it, remove the plate, but leave him in his chair, while you keep chatting as if nothing happened. Do not jump and offer something else, the second he pushes the plate.
My advice is to have him next to you when. you cook, either in his high chair so he can see , and let him participate in the preparation, handing you the carrot or whatever, maybe teaching him how to brush a zucchini before putting it in the oven, sprinkle rosemary over a chicken breast, turning on the blender for the soup and so on.
Cooking starts at the supermarket when he helps you pick vegetables, give him the bag and ask him to fill it with green beans, then at home wash them in a bowl , and so on.
Eat together. At the table. The same meal. Don;t talk about the food "don't you like? You don't want it? " talk about the plans for the afternoons, the books you are going to read. before bed, even bring one and read it