The Museum of the Second World War is an impressive museum that explores the various aspects of World War II, mainly from the Polish point of view. However, I wonder if the pretense of covering such a broad subject does not make him somewhat flattened. For example: To relate to the general hunger created by the war in the same way as to refer to the deliberate starvation of populations in concentration camps, ghettos, or prison camps seems problematic to me. But after saying that, I think it's a significant museum, and recommend visiting it.
You should clear at least three hours exploring the museum exhibitions.