Also accepted was "Clean up your room". Agree c Biomax, an exclamation point makes it an order!! If a question mark at end, it reflect's a parent's incredulity of a child spontaneously cleaning without coercion... 9Sep15
Tidying and cleaning are used interchangeably these days, but aren't the same thing. Tidying suggests creating some sort of order/neatness, while cleaning suggests getting rid of dirt by dusting, vacuuming, mopping.