This reminded me of a few films (Sting, Infested) and that's no bad thing - very atmospheric and gave me the itch...you know the one - the itch you get when you kick over a rock and an eight-legged monstrosity scuttles away. As someone who has acutely arachnophobia, this set my teeth on edge playing throughout.
I felt this was just a prologue to something that could be much larger in scope and design - I was curious about the main character and why they would keep pets if they had recurring nightmares about being chased by large versions of them! You could also have the whole apartment block as one big escape scenario - with some puzzle elements and ways to barricade rooms from X-33.
Dev - If you decided to expand on this I'd keep the eerie, dread like tension throughout - you could be onto something special here...