Are 15 balloons enough to lift a kitten to a height where the balloons and kitten look like a dot from the ground?
Answer: IIRC Kittens are weaned at 6-8 weeks. Assuming this kitten was adopted out at 6 weeks, it would weigh approximately 650 grams, at least. Assuming this balloon was filled with helium and roughly the size of a standard amusement park balloon, it could lift about 14 grams.
14 x 15 = 210 grams of lifting force applied to a 650 kitten, not including the weight of the collar, balloon cords, or the balloons themselves.