This isn't exactly an uncommon practice for the Canadian government, nor for its provincial governments. First the federal government has an incentive because #1 it boosts revenues, #2 it boosts educated immigration (Canada, like the US and many other countries just need to get most European immigrants into the country and they'll find they love it in seconds) as most game firms hire internationally, and #3 it makes good publicity. The provincial governments are offering their own subsidies for much the same reason.
Canada has a high rate of fluent English and French speakers, which makes it an ideal place to develop games for the international market as both languages can easily be done 'in house'.
My husband works for a well-known game developer with offices in Quebec. Thanks to the subsidies, Montreal is the only city in the world where a programmer costs less to hire than in Shanghai. As a result, they have a virtual hiring freeze anywhere except Montreal, where they can hire as many developers as they like.
The main drawback is that the language laws in Quebec essentially require managers to be bilingual, which makes recruitment more difficult. (Employees in Quebec have the right to be managed in French, if they choose)
Canada has a high rate of fluent English and French speakers, which makes it an ideal place to develop games for the international market as both languages can easily be done 'in house'.