Of course, the game deserves all the praise haha! As for my interpretation, at the start I thought the main character was either coming to terms with their own death or an otherwise terminal condition, hence why they were stuck in the room and it kept becoming more and more disconnected from reality as time went on. But eventually (and especially with the ending) it became more clear that they were instead willingly locking themselves in, with the "locked door" being more of a metaphor for a mental barrier preventing them from facing a conflict in their life (which I assume has to do with their strained relationship with their parents that makes the protagonist feel like they don't belong, as they seemingly decide to run away from home at the end). As for the characters I think each of them represents a part of the protagonist's inner thoughts, with the frog being toxic positivity as a coping mechanism, the cat being a far more pessimistic (yet grounded) view and Oscar representing self actualization itself, hence why his arrival is uncomfortable, drives all the other characters away and overwhelms the protagonist. I also thought the character's presence (and further lack there of) itself was a way to explore the out of place theme, as their initial arrival feels paranormal and their style clashes with the room's, but later on their sudden departure, despite leaving the room "normal" again, instead feels uncanny (out of place, one could say, haha) as we've gotten used to their company. It shows that things can feel out of place both in presence and absence, which is a very clever perspective on the theme.
Sorry in advance for the giant wall of text haha. I'll be looking forward to the video!