Travis Bruno of Capsule Computers writes:
"When an anime is created to help promote a game, it can range become something memorable, even anime based around card games. Sometimes these series stand out on their own; other times they are simply an advertisement used to advertise a game. The case of Leviathan – The Last Defense is a bit unique however as the game it is based off of was a digital iOS game by GREE in Japan that actually was released as the anime aired. As such, is Leviathan – The Last Defense more than promotional material?"