When you say ‘this’ course, which course are you referring to? Or do you mean course of action? I take the latter meaning for the rest of the answer.
The answer depends on which country you are in and whether it has a large number of game development studios. Again, I assume that you are in the UK or the US.
Junior designer positions and even senior positions are really hard to come by and generally designers are from other disciplines in the industry such as programming and art. Generally, there are more positions in programming and art disciplines compared to design.
Also bear in mind that as with any skilled industry, it will not be easy. You may find that you don’t have the ability for the roles you apply for which does and has happened.
In my opinion, you are not yet too old for the industry although you may find it a challenge when applying for junior roles when pitted against fresh out of University graduates.
The games industry definitely has some legs for a fair while so I wouldn’t worry about it dying out just yet.
There are options for you as well which includes University as a mature student.