Starman this time is out to thwart a country of loons who want to nuke the earth, starting with Japan! Starman is sent to Earth to give these baddies a knuckle supper and to stop radiation spreading through the universe (which is full of radiation anyway, let's not think about it).
Of course there's kids here to help Starman out, if you can call stealing nuclear material 'helping'. Also, some cops, a nun, and others you won't care about because these films are all about the arse kicking.
This one is definitely lacking in Scary Monsters (and Super Creeps). There's no lizard men or...whatever those aliens in Evil Brain from Outer Space were...or even any Evil Brains. Starman does manage to survive a nuclear blast before taking on about fifty guys at a time though.
Got to agree with the majority though...this should be one of your last Starman choices - Evil Brain and Invaders from Space are much better.