There's something entirely pointless about reviewing movies after opening night in the Summer of 2009.
Even as showbusiness falls apart, the summer schedule is glutted with a little bit of everything from Sandra Bullock vehicles to trainwreck movies inspired mostly a lust for nostalgia (I'm looking at youGI Joe). To last more than that first weekend it takes something special, or something with enough marketing inertia to carry it past poor word of mouth.
In that environment it doesn't look good forYear One. The Jack Black and Michael Cera caveman buddy comedy manages to deliver exactly what it promises, the two actors stuck in their usual places inside of world of dick jokes and hastily assembled biblical references (not that there's anything wrong with that).