You create a rolling sphere of churning water that can engulf those it strikes. The aqueous orb can move up to 30 feet per round, rolling over barriers less than 10 feet tall. It automatically quenches any nonmagical fires and functions as dispel magic against magical fires as long as those fires are size Large or less.
Any creature in the path of the aqueous orb takes 2d6 points of nonlethal damage. A successful Reflex save negates this damage, but a large or smaller creature that fails its save must make a second save or be engulfed by the aqueous orb and carried along with it. Engulfed creatures are immersed in water and must hold their breath unless capable of breathing water. They gain cover against attacks from outside the aqueous orb but are considered entangled by its churning currents, takes 2d6 points of nonlethal damage at the beginning of their turn each round they remain trapped. Creatures within the orb may attempt a new Reflex save each round to escape into a random square adjacent to the aqueous orb. The orb may hold one Large creature, 4 Medium, or 16 Small or smaller creatures within it.
The sphere moves as long as you actively direct it (a move action for you); otherwise, it merely stays at rest and churns in place. An aqueous orb stops if it moves outside the spell’s range.
I at first thought you could move the orb in any direction, including upwards into the air, but reading the bolded part, it's giving me the impression that the orb is landlocked.
You are correct. Aqueous orb is similar, and better in almost every way to a flaming sphere; bigger, more damaging, more hindering, can roll over higher barriers, etc. However, unlike the flaming sphere which can leap up to 30 feet to strike flying opponents or reach higher elevations, the aqueous orb must remain on the ground (possibly it can churn across the surface of water, which the flaming sphere also couldn't do).