According to Spanish Director Nacho Vigalondo (“Timecrimes”), “Colossal” was greenlit by the studio because Anne Hathaway championed it. Hathaway saw a chance to play the avenging female who fights back against male physical abuse. The Oscar-winning actress (“Les Miserables”) jumped at the opportunity.
It’s too bad Hathaway and Vigalondo didn’t take this homage to Japanese kaiju movies and Godzilla one step further and have the two main characters (Anne Hathaway and Jason Sudeikis as Gloria and Oscar) represent the symbolic influence that the United States has in the world, for good or bad on a colossal scale. Now would have been a particularly good time in history for that approach.