I feel like I'm reasonably good at picking at a game on the gameplay level, as per what works and does not and why and surface videogame essayist stuff like ludonarrative dissonance (or the rare examples of ludonarrative harmony).
I may offer you my finest insight into video games such as "Lara Croft has some sort of father complex going on" and "Shadow of Chernobyl is unintentionally about life in the collapse of the soviet union" which even by my own admission feels shallow and trite. You watch someone like Jacob Geller or Noah Caldwell-Gervais and they have fascinating things to say even on games you wouldn't expect it, like NCG on Quake.
How do I become that knowledgeable? Interesting? Analytical? about video games?
Reading Roadside Picnic now. Feel like Ogre though and not getting the deeper themes.
Always ask, what, how, and why. If you really want to dig down, ask WHY for EVERYTHING - start small (grammar and punctuation) and then expand to themes, symbolism, allusion, etc. There isn't a lot of things that authors do "carelessly". Authorial intent is everything. So ask why of everything. Sometimes the answer won't be in the next sentence, it might be at the end of the book. Then check what questions were answered and which ones weren't. How can you answer those questions with the text. Etc.