The content of this pretty predictable affair notwithstanding, let's take a look at some of the critical acclaim this movie has garnered, starting at about 0:35: "The best giant monster movie I've seen in years." Which really narrows down the scope as far as superlatives go. It's sort of like saying, "Of course I like your cooking, honey; this is the best Tuna Helper made by subbing out milk with artificial creamer because there wasn't any milk I've had in years." Also, consider that that quote comes from Ain't it Cool News, the kind of unabashedly fanboy website that us unafraid to use words like "nifty" in headlines and seems to exist specifically for the purpose of providing short, gushing soundbites for goofy genre flicks. Note also that Ain't it Cool provides two of the three quotes here, the other one being simply, "Awesome."
Meanwhile, IGN, another techie website for fanboys, calls Monsters "Utterly unique and original" -- which seems to contradict Ain't it Cool's assessment. If it's utterly unique and original, then how can it be categorized as a "giant monster movie?" Or maybe it's just utterly unique and original within the genre. Or, maybe it's a giant monster movie that is also a detective noir film and a romantic comedy. Now that would be unique.