How do you fit a video game's interpretation with its source files?
Given a movie with ambiguous story, you have multiple options to base your interpretation upon: you have the movie itself, the screenplay if available, what the author said in interviews or books, etc... Now, if we take a video game, you also have additional tools: the source code, the installed file names, unused resources, etc. There are of course a few games that expect the player to check these files but that isn't what I want to focus on.
Would you say that all these files have the same authority as the game itself when it comes to interpretations?
I'd like to take an example with SPOILERS FOR LIFE IS STRANGE 1, as this is the game that sparked this topic for me:
The blue butterfly has a special place in this game, it is what starts the whole journey when Max takes a picture of it and Chloe gets shot. It also shown again in the 'Sacrifice Chloe' ending during that same scene. And later during Chloe's burial that butterfly is shown to land on the coffin in front of Max and fly away. There are some scenes that imply that spirit animals are a thing in the in-game universe. After finishing the game my interpretation was that the blue butterfly was Chloe's spirit animal. Now what a surprise to see in the game wiki that the texture file for that butterfly is named 'Spirit_animal_Chloe' !
Is there any room left for interpretation when the source makes it explicit text? Or can the source be reasonably be pushed aside?
It's helpful not to get bogged down in looking for an authoritative reading. Different readings / interpretations operate under different frameworks so they can achieve different goals, the best approach is the one that sheds light on what you're trying to do. If I was examining Life is Strange in terms of its cultural impact, place within its genre/time, or anything else that's more about its real effects on people then I'd probably ignore that. But if I was doing a personal response and doing so to explore my own relationship with art? If that was interesting to me, that could be a really cool path to go down. Just depends on what you want from it, you don't need to pick an interpretation.
At most we might be able to say that many of the ways that that information would be used are just appeals to authorial intent and argue against that for all the reasons which we normally would. But it's clearly not all of them, since some will read that as part of the text, so even that's a flimsy point.
I personally wouldn't do much with it, but it's plenty valid for many kinds of analysis and readings.
What matters most is absolutely your interpretation of the game. In the scope of your example of Life is Strange, that game is meant to put you in situations which evoke emotional responses—like the decision you have to make with alternate-universe Chloe. I think the game wants you to really wrestle with the Sacrifice Chloe ending, and interpret what the butterfly means for you. (I mean, the blue of the butterfly and the blue of Chloe's hair already share a strong tie too, so your personal conclusion isn't exactly a stretch either.)
Now, with that aside, I'd argue that source files can further inspire your reasoning, but don't necessarily count as canon. The art that you take in is the game experience itself. Things left behind in source, such as unused files, localization keys, etc aren't what you directly consume while playing the game, so they should be taken exactly as that—potential vestigial context, but not necessarily canon.
In the whirlwind of the game development process (where nothing is ever "done", you just stop working on it), do you think the wide array of game developers, producers, and writers are all agonizing over the precise naming of files or sanitizing in-development content? I don't think so—they're focusing on the game experience.