The word that comes to mind upon playing COP: The Recruit is "Unpolished". In some ways, this is an amazing game. It is no exaggeration to say that COP has the best graphics of any game for the DS. The world of New York is huge in this game, and impressive to explore. The only problem is, there's not a whole lot to do in it. There's no money to be earned or spent, gratuitous driving violence is limited to the T-rated level of knocking over the occasional trash can, and, when not on a missions, you're pretty well limited to taking photographs (of, admittedly, impressively rendered landmarks) and knocking down barricades, but there's no real reason to catch 'em all. Compare this to the GTA or Saints Row series, where there is all sorts of havoc to wreak, yes, but if you want to jump in a firetruck and put out fires (or randomly troll people by spraying them with a hose), you can do that to. Here, a firetruck (or a taxi, or an ambulance, or a police car) is just another car, with worse handling than the others (and believe me, their handling is pretty bad to start). This is only one example of the rough edges apparent in COP: Guns with hit-or-miss accuracy, vehicles that you can only damage from the back instead of the side, cars that will drive perfectly until a random last bit of damage, then randomly explode into nothingness... This wouldn't be so bad if Grand Theft Auto: Chinatown Wars didn't exist. Unfortunately, it does everything COP does, and better. COP may only be a 4 star game to GTA:CW's 5 stars, but second place is the first loser.
The story missions then do most of the work in carrying the game, and, for the most part, they're pretty solid with a good variety. Some of them definitely show the limits of the engine: it's hard to chase after a speeder when draw distances mean you'll have to deal with cars appearing out of thin air, and some of them have victory requirements that can only be described as artificially difficult. The GAME OVER screen will pop up a lot, and for the flimsiest of reasons. Was failing to catch up with that speeder, REALLY going to send me to the hospital? Still, the plot is twisty and interesting with some memorable art and characters.
Overall, COP: The Recruit doesn't live up to the full potential of its engine, and with so many annoying details to pick apart, its no wonder reviews were negative. However, at its core is a solid action title for the DS, especially for those who wouldn't mind that the Wide Open part of the Wide Open Sandbox might be a little neutered. I realize that "it's not that bad" isn't much of a ringing endorsement, but this is a budget title unfortunately initially released as a full-priced entry. If you can pick it up for under $10, you'll find it well worth your time and money.