The art is cute, and there are a lot of nice touches in the presentation (opening credits! that's a rarity) that already make for an evocative opening before a single line of text appears. In particular, the minimalist title screen really works here, setting the mood instantly and providing a fun transition to the game proper.
There are, though, are a couple of formal things to make note of. I thought the pauses were perfectly calibrated in the tense scene outside earlier on, but for the later character drama bits, they came off as a little extraneous; could have let the prose set the pacing in a few places there. Sprites are used in a weird, inconsistent manner, with the protagonist sometimes being displayed and sometimes not, although I guess it works as a means of allowing scenes to be blocked with more variation, important with there being no expressions.
As far as the story goes, the first half is strong – the dialogue feels natural, all the setups pay off, and despite the aura of familiarity surrounding the premise, there's an arresting sense of rawness and vulnerability to the execution. I was less enthused with the climax, however. WALLS is absolutely gripping when it lets its imagery and atmosphere do the talking, but I feel like the ending doesn't demonstrate that virtue; it goes a little too far with explicating everything and laying out what this means for everyone, ultimately being more of a slow dissipation than a punchy final point. Still, it's a pleasant read and a good jam entry.