How do you defeat Mr Freeze in Lego Batman

Keep a little distance between yourself and the Mr. Freeze, and he will try to use his freeze gun. When he does, run circles around him, so he can't hit you. When he tires, punch him and he will retreat to the upper level and switch on a fan. Destroy the fan by building a cannon and firing it at the fan. When he fills the tanks with lava jump across and pull the lever to reveal pieces. Put them together and push them to the wall, dropping a block of ice on top of Mr. Freeze and knocking him back to the floor where you can punch him again.