Videogames are made in a myriad of different ways, by a myriad of different people with different skills. From experimental artistic games to billion dollar corporations, it takes a huge range of different skills and different people to make games as we know them!
Honestly there are lots of paths in games that branch from Illustration skills: you could dabble in Concept Art, which focuses a lot more on design, idea generation, and early collaboration for pre-production.
