Considering it's expected for an adaptation to include a series of changes to better incorporate itself to the new medium, we can say that the movie is pretty faithful to the source material - In the sense that it took a book that had good ideas, but amauterish execution filled with tiresome exposition, and made it into a movie that ALSO has good ideas, but amauterish execution filled with exposition. But they forgot that the book had at least some emotional investment.

If you want that much to see an action movie with young protagonists, nerd references and pretty visual effects, watch Scott Pilgrim. It has the same theme of video games immersed in the daily life, with 10 times more personality. But if you're actually interested to see a bastardized adaptation with pooly written characters, I suggest Death Note (2017). Both are available on Netflix and will save you the ticket money.