> a video games first purpose is to be a commercial product,

That rather depends on the video game.

> where as art is something created for the sake of expression

Quite a lot of what is universally recognized as art was created for commercial purposes by the artist; no small part of it was also shaped by commercial interests of those who commissioned it.

I don't see how that makes games different from other forms of media, you could apply the same argument to high budget blockbuster movies.

Games present more options for commercializing, but at the same time I think that games have a lot more moving parts that can be seen as forms of artistic expression

There are a lot of games which are definitely not created primarily to make money - or at least, it might be the artists only way of making money but from another studio it wouldn't be considered a commercial cashgrab.

Pathologic, for example, is not exactly a FIFA game