Lots of really cool ideas here! So far I've just played the "traditional" route (ie: not using the secret code you provide). But so far I can see that your not just borrowing from Petscop but building new stuff on top of it. I like the fact that you can't hold things through doors but you can cleverly "cheat" that mechanic by taking advantage of how long doors stay open. The melody mechanic is really neat. I especially like how "O+K" was how you continued.
I almost think it would be better if you didn't use Petscop assets. I think that this game could have stood up on its own as just a "petscop inspired" game rather than being so directly tied to it. I also think that providing the hint that "[Laura] is the in-universe developer and narrator of the game. " in the description is a bit of spoiler, I think I'd rather discover that in game rather than read that in the description.