The first and most striking thing a player might notice about City 7: Toronto Conflict isn't the frog-masked alien police skulking around North York, nor the crystalline barriers that have sprung up on Yonge Street. It's the street furniture.

There, on the curb, is an unmistakably Torontonian solar-powered parking meter. Next to it, a distinctly local no-parking sign. Then there's an alien threatening to bludgeon some oppressed locals, but, hey, isn't that a bike chained to a post-and-ring stand?

The creators of this local-flavour shoot-'em-up have recreated the ambience of the city's streets, squares and subways in detail that leaves other video-game Torontos looking crude as Pong. It's the product of George Brown College's game-design program, where a team of five students and two faculty members turned a class assignment into a full-blown project that is making waves across the Internet.

"We have a philosophy of 'the city as classroom' here," Luigi Ferrara, the director of George Brown's school of design, says in what might be an understatement. "The students were forced to go out into the city, to capture and recreate the city."

Toronto Conflict, which can be downloaded free, is a "mod" — a user-created modification — of Half Life 2, one of the most popular and critically lauded games on the market. The Half Life series tells the story of one Gordon Freeman, a scientist grappling with a trans-dimensional rift through which all manner of nasty aliens have emerged to enslave humanity.

In the George Brown variant, Mr. Freeman's travels through a post-apocalyptic Eastern Europe are disrupted by a teleportation accident; he winds up in Mel Lastman Square.

"Gordon Freeman?" stutters a local. "What are you doing in Toronto?"

Good question.

The project started out in the classroom of Sean Guadron, a game designer and the co-ordinator of the George Brown program. Mr. Guadron's class had been learning to work with the Half Life game engine, so the decision was made to apply their skills to an all-out simulation.

To recreate Toronto scenes with such fidelity, the team started off by laying out blocks with the help of Google maps. Then, to capture the city's finer textures — from safety signs in the subway to the markings on newspaper boxes — thousands of digital photos were taken and manipulated.

Shapes were modelled, storylines were written and character dialogue was recorded. The result was a multilevel game that takes players from North York, into the subway, across Dundas Square, past the Eaton Centre and through St. Michael's Hospital.

The team is now planning to extend the game south, through the PATH underground walkways, to the CN Tower, which, inevitably, the aliens are using for no good.

For Mr. Ferrara, the game marks a first step in a broader project back in the real world. "I really believe that we need to build a virtual replica of our city," he says, "not just for gaming purposes, but for simulation purposes, for planning purposes." Such a model, he says, could be as useful for city staff as it is for designers making more games set in Toronto.

For the students involved, the game is more than a learning opportunity. Erza Lee Arrilano, a team member who has since graduated and is now on the job market, says game makers keep an eye on the "mod" community, looking for bright ideas and talent. "If your idea's good enough, it will garner attention and turn some heads," he says.

The game has certainly sparked interest on the Internet (one online wag pointed out that the North York City Centre really does look as post-apocalyptic as it does in the game).

And so far, the game's violent nature hasn't attracted many detractors.

"It's not like the point of the game is to plan a terrorist attack in Toronto," Mr. Guadron says. "It's about you trying to liberate your city from aliens that are occupying the planet."

Failing that, there's always the ineffable joy of plowing down alien fascists with a National Post box.

Special to The Globe and Mail