This is a very good game, but to get the most you need to make some changes. Personally I changed the controls slightly (switched to an alternate scheme) and then I changed the camera to tele and zoomed out a bit.
Once you do that, then the gameplay is a lot better. Gameplay is a lot slower than some recent fifa's on other consoles, however, personally I think it makes for a better fluid passing game, and it's also more realistic.
The other camera modes are fine for street games, and the 3d effect works well giving a great sense of depth, unlike many other 3ds games, it does add something to the game - but for the normal matches, I'd turn the slider off, as it doesn't add anywhere near as much.
The new feature of being able to shoot by touching a virtual net on the bottom screen works really well sometimes. When outside the box looking for a pot-shot, or at the edge of the area, it's well worth it, but for aerial balls and placed finishes in the box (where you can't take time out to look at the bottom screen) it's best to stick to the buttons.
A plethora of teams and leagues can be found and they've crammed a lot onto the card in terms of game modes too, however the other reason this is a 4 star game for me is the lack of online functionality. This isn't a rushed game, EA have spent time and it's really telling they developed it specifically for the 3ds, but as a result of that - the lack of online is slightly more annoying, however, there are online squad and kit updates for free, which is a plus.
In the career mode, you can get a deep lasting experince, however, the transfer system is a bit simplified and you can only buy/sell a certain number of players per window (you get a certain number of "bids") however it's compensated for by a good development system, and lots of things like training, scouting, street match friendlies etc
I wouldn't recommend this for kids, because it might be fiddly for them to set it up right, and as I said, you need to make alterations to get the most out of it, and besides, they'd probably prefer a more fast paced arcadey game than the slower tempo of this game, but for teens and up, this is a cracking football game for the 3ds, and is comfortably better than PES, providing a richer more realistic experience jam packed with modes and features, with online multiplayer it would be a 5 Star game, but it's definitely worth the purchase without it, and so I'm giving it 4 Stars.
UPDATE: Having played this for a while now - it's not as good as I first thought, the gameplay becomes quite one-dimensional and the slow tempo becomes.... lethargic.... I'd actually recommend PES 2012 3ds ahead of it now.