Hulk tried to move the wall of a fortress, but unfortunately, he was unable to do it. However, he applied a very large amount of force to do so, hence work done is positive.
Work is said to be done only when a body displaces from its position by the influence of the force acting on it. If the displacement is zero even if a large amount of force acts on a body, the work done remains zero. Here, in the example, since Hulk was unable to move the wall, the displacement is zero and irrespective of the large amount of force he applied, work done is zero.