FALLS CHURCH, Va. – For about a week my 6-year-old son, Mark, was having a grand old time on Webkinz, one of several children’s Web sites that have exploded in popularity in the last year or so.

Then it dawned on him. His online pet, a gorilla named Ben, was playing games like “Rock Paper Scissors” and “Go Fish” against the other denizens of Webkinz World, nearly all of whom were pink kittens or fluffy-maned horses.

“Is PoniesRock!24 a girl?” he asked.

“What difference does it make?” my wife and I responded.

“Yeah, but is PoniesRock!24 a girl?”

We finally conceded: “Probably, yes.”

Click.

He quickly reconciled his little internal conflict and was soon happily back on track. And that was fine with us. Webkinz is one of the few sites that has captured our son’s attention without aggressive promotional tie-ins for superhero movies or television shows. He doesn’t need a lot of parental help to navigate the site.

And Webkinz has broad appeal.

While it seems that the sweet spot in the Webkinz demographic – what with the cutesy-pie graphics and the proliferation of fluffy felines in pastels – is probably the preteen girl, the site has something for everybody. When we boot Mark off the computer to go play outside, either my wife or I will often play a few games before we shut it down.

To log on to Webkinz, you first have to buy a specially designated stuffed animal for about $15 or so. (The toys themselves appear a little cheaply made, like what you’d find at a roadside carnival. My wife has already had to stitch Ben up twice.)

The price compares favorably with another popular site, Club Penguin, which charges about $60 a year for full access, though limited features are available free.

The toy comes with a code giving you one year’s access to the Webkinz World site at webkinz.com. There your toy gorilla or cat or frog or bunny becomes a virtual pet, and it’s your job to keep it happy, healthy and well-fed.

You do this by “buying” food, toys and amenities with Webkinz cash, which you earn by playing the games and fulfilling various tasks.

Or just buy another stuffed animal – you get 2,500 or more in KinzCash for every subsequent toy you purchase, compared with 3 to 50 by playing games. That is assuredly part of the reason many people seem to collect dozens of WebKinz toys.

The huge variety of games and activities is by far the site’s best feature. Some are habit-forming and addictive, including math, word and shape puzzles in the vein of “Tetris” or sudoku. Most reward critical thinking in some fashion or another.

Some games appeal to the very young – my 3-year-old laughed uncontrollably at one game where you whack a puffball-type creature with a club – and others appeal to adults and teens. I suspect many players are adults, either using their children’s accounts like we do or childless adults who have moved on from their Beanie Baby collections.

The games can be played solo or two-player, and the Web site will usually find you a challenger in seconds. You can see the site’s appeal to adults late at night, when the arcade is still hopping and the level of competition on those word puzzle games rises dramatically.

Some of the games seem complicated even for older kids. A dice game that is apparently popular was a little confounding. Mark needs help playing some games, but can do others by himself. The variety is sufficient to please everybody.

The lack of advertising on the site is also welcome. The Web site provides rewards and incentives for buying additional toys but does not seem particularly aggressive in pushing kids to spend real money. Some features, like tending to a garden, reward players who log on to the site every day. My wife says it promotes responsibility, though I find it mildly obnoxious to insist on my child’s daily participation.

The ability to outfit your pet’s living quarters is also staggering. Thousands of virtual items are available for purchase, from custom towel racks for the bathroom, swimming pools for the back yard and designer clothes for your pet to wear.