Would the Icy Prison spell work differently against incorporeal foes? I'm asking because I haven't been able to find anything about it, but this sentence under the Incorporeal monster rule makes me wonder if there's any specific interaction:
Incorporeal creatures cannot make trip or grapple attacks, nor can they be tripped or grappled. In fact, they cannot take any physical action that would move or manipulate an opponent or its equipment, nor are they subject to such actions.
Of course this is beside the 50% chance to affect incorporeals.
So, would the spell work but the creature could move out of the ice, could it only make incorporeal creatures entangled or would it not work at all?