In WWII, Captain Invincible used his superpowers against the Nazis and was hailed as a hero. But when he was accused of treason, he retired to Australia in disgrace. Cut to the present, when a US super secret super weapon is stolen and he's asked to come back to the States in order to help stop evil and restore his sterling reputation. Unfortunately, Captain Invincible is a drunk now...
It really looks like they had some fun making this movie. Every scene has something weird going on, mostly in the background. Worthy of repeat viewings to catch some super fast gags. Every second Christopher Lee is onscreen is pure movie gold.