The Call of Duty spinoff for PlayStation Vita was released alongside Black Ops 2 yesterday (November 13), and has seen lower-scoring reviews and online impressions that slam the game's short campaign and "unplayable" multiplayer.
Pocket Gamer awarded the game 4/10, saying it is too easy, can be beaten in 45 minutes, and relies on difficulty spikes to slow progression.
"It's not difficult in the slightest, missions are short, and if you're a seasoned Call of Duty player, you can probably beat the entire story mode in 45 minutes," said reviewer Peter Willington.
"However, the game attempts to counter this by being brutally unforgiving in certain spots, usually by adding hostages or a timer."
Multiplayer was said to be the "worst offender", with only a handful of matches played in two hours of attempting to connect to servers.
Willington concluded: "Everything about Declassified is a massive middle finger to the fans. It's a £45 mistake for you to make this Christmas, driven to purchase it on a wave of excitement from Black Ops II on PlayStation 3 or Xbox 360.
"It serves no purpose but to frustrate and annoy, with lacking single player, little use of the potentially fascinating BLOPS universe, and almost totally broken multiplayer."
Other critics have been writing about their experiences on Twitter before posting their reviews, with Game Informer associate producer Dan Ryckert reiterating the sub-45-minute story mode complaint, while another mode took "barely over five minutes" to complete.
"Black Ops: Declassified has less than an hour of single player content in total," he said. "That's not counting attempts where I died, but that wouldn't add much to the total."
Ryckert said there is another horde-style mode which could "add a bit" of time to the length of the game, before adding: "But I have no idea why someone would want to spend more time with this".
He added that his review will be postponed until Activision comments on the state of multiplayer servers, which are currently "unplayable".
Photo gallery - Black Ops 2 midnight launches:
Copyright: Michael BowlesElsewhere, Giantbomb's Jeff Gerstmann said: "Don't want to freak you out, but my initial impression of this Call of Duty Vita game is that it's ass.
"Just when I think I've seen all there is to see, Black Ops: Declassified breaks in a new way. Wow."
He added: "I can only imagine what the poor people buying Vita bundles with this game in it must be thinking."
Black Ops 2 is available now on Xbox 360, PS3 and PC, and is on course to be the biggest entertainment launch of all time.
It will also be available on Wii U from November 30.
> Launch guide: Everything you need to know about Black Ops 2
> Black Ops 2 review round-up: Critics score the latest Call of Duty
Watch a trailer for Black Ops: Declassified below: