As Frob says, financially speaking, game development is about the worst thing you can do with the requisite skillset -- that is, someone qualified to do game development, whatever their level, can certainly earn a higher income using those same skills (e.g. programming and all the things that go into it -- not "Unity 5") elsewhere. Unless you're lucky enough to be a founding member of a studio, occupy a real position of power in the company (e.g. someone who sets the technology directions for the entire studio or manages multiple teams of people) then you're unlikely to even achieve a salary that is common in other industries. The disparity can be pretty marked -- I've known games industry jobs to offer half to 2/3rds the starting salary of other places, it tends to get closer to the 80% range once you've shipped a title or two, and then doesn't really change unless you're really a stand-out. Not only are "high" salaries in the games industry lower, they're also less common to see, in my estimation. Likewise, bonuses tend to be lower and/or less frequent.

I don't think anyone would advise to become a game developer for financial reward alone. You need to really enjoy the work itself (not just the end-product, either) -- loving games does not equal loving making games. And if you don't love making games, its going to be really hard to stomach looking at people with similar or lesser skillsets making more money than you, not working 50 or 60 hours per week, having time for their families, and being able to afford nicer things for their families. I don't want to make it all sound too stark, because there's a lot of reward there for a certain kind of person, but you shouldn't go in with rose-tinted glasses either.

I agree with the above. Buuuut if we're talking about the best paid game dev jobs, it's going to be highly capable system architects well versed primarily (but not exclusively) in C++ and various low level technologies like DirectX 12, GL/Vulkan, etc. People with deep and heavily mathematical knowledge of graphics and/or physics probably do best, as they're very difficult to replace. The web and engine-specific guys just don't merit the same levels of compensation.