Pros
The recruitment and mobility team, that helps with securing an interview and helping with the relocation, is amazing. 5 stars! Ubisoft takes good care of their people in general: Courses (French and professional types), a gym, health care, lots of events, both for employees as their spouses and children. Montreal is an amazing city, the people are really nice, there is also always something to do. Some interesting AAA titles to work on, not much overtime.
Cons
Politics are hell. It's about who you know, not your skills. I hear and see it all around me so it's not only limited to my situation. Some incapable people work here in high positions, looking down at the rest because seniority is decided on how long you work there, not skills... You're not supposed to say anything about it, it's not your place. It's a classic example of kissing upwards and kicking down. Also, working in insanely large teams, so you often end up being limited to one small component in the whole cycle. The work gets dull, repetitive, not enough challenges. Also, it seems that non-French speakers are limited at what they can accomplish in the company because some teams prefer to keep their inner circle small and ... well, French. I've heard of teams that had their meetings and communications solely in French, and some people ended up having no idea what was said and what was expected. This way, you really get 2 types of groups: expats VS Francophones. Also, people just get lifted from the projects they are invested in to work on other projects that are reaching their deadlines, sometimes there even is no work for them and they sit there doing nothing until someone in management figures out there's nothing to do for the guy and he's sent back to his old team, who now is also behind on schedule and the whole circus starts again.