Unlike many indoor amusement parks , Nickelodeon Universe has a great deal of natural foliage in and about the park , and its floor has a wide variance in height - the highest ground level in the park is 15 feet above the lowest . Unlike many indoor amusement parks , Nickelodeon Universe has a great deal of natural foliage in and about the park , and its floor has a wide variance in height - the highest ground level in the park is 15 f above the lowest .