I think this is a solid start, particularly because it uses the core tools of Twine well. I think there is definitely more that can be added, so you will have to prioritize. These are some exciting things to try moving forward:
- Mechanics: It would be good to truly have the option to explore outside the house, even if the results are not ideal. Who knows? Maybe there is something useful out there. It is worth exploring the idea of a timer in those crucial moment
- Story: It will take a bit more development to avoid cliches and stereotypes common in zombie stories (specially now with The Last of Us and what not). What is your unique take on the genre, or the characters that live in these storywolds? Even a bit of backstory, or some novel and surprising take on zombies could help. Maybe start the story with some background text, to develop this further?
- Art: Well, right now there is not much to look at, but this could be sick. I find the imagery of the husband with the note in the entrance terrifying and mesmerizing. Maybe time to illustrate that? What about the zombified wife? This is all very evocative, so give us some cool illustration too!