Some more notes
Cuphead - The main team is Toronto based, but all the coders were here in Ottawa. Some of which I went to school with. https://store.steampowered.com/app/268910/Cuphead/
Tunic - I believe they are all Canadian. At least one of the dev's is a local to Ottawa. https://tunicgame.com/
Spring Falls - By Eric. I remember seeing the early demo's of this at our local game dev event. https://www.springfallsgame.com/
Gataela - By Paige who is really nice. She helps curate the first link I sent. https://www.gataela.com/
Spectrum Break - A game I released solo before joining Skypyre. https://spectrumbreak.com/
We've had a few phone app game companies spring up around Ottawa but I honestly have no idea if they survived the pandemic. I haven't seen Magmic in a long time and I recall them not doing too well.
I'm also pretty sure Balatro is Canadian.
I believe the Momodora series is based in Toronto, as is the developer who made Mount Your Friends but you would have to verifiy both.
Another big name are the developers are Warframe. They are based here in Canada.
King of the Hat was by an indie team from somewhere in Ontario. It's too bad I haven't had the chance to see them at an event in a while. I hope they're doing well. https://kingofthehat.com/
I also hate to link to reddit now, but months ago there was a reddit post with a big list of Canadian devs and games.
https://www.reddit.com/r/BuyCanadian/comments/1iku9sm/canadian_game_designers_to_support/