Hey grats, welcome to the studio. They're not putting you up in a temporary place?
A popular place to live is the Plateau area, but the rent can be a little high then usual.
Neighbourhoods that are close to Gameloft are Mile End and Rosemont. I live in Outremont which is also close, however I take a 15min bus to work. Ideally you want to try to live close to the Orange Line Metro because it's the major subway line that runs through Montreal. And in the winter, you can just go underground as opposed to waiting outside for the bus. But overall, it's quite easy to get around by transit and even by walking. I haven't felt a need for a car at all since I got here.
Also, if you don't know yet, http://www.padmapper.com/
is a great tool to look for places to rent. On that note, there are tons of places available pretty much all the time. So you can also just walk around the neighbourhood that you like and look for the "A louer" signs. Talking with the landlords, on the other hand, may be tough depending on how much English they may know (or how much French you may know)
Lastly, most of Montreal seem to use http://montreal.kijiji.ca/
over craigslist. So run a few searches there for rentals as well