This was a really cute game! I'm not sure exactly which assets were original, since you said you didn't make all the assets/code from scratch, but I very much liked the art and music regardless. I think the level design was very intuitive, dialogue was funny and helpful, and I appreciated the credits/outro section you had at the end.
The one thing I would improve upon is the physics and collider placement. The cats colliders could have been a little smaller. And I found some random level colliders that weren't associated with sprites. Also, for movement, I find GetAxisRaw is better than GetAxis, bc it feels more responsive. And the player gravity multiplier could be higher to feel less floaty.
Overall, great work! Keep it up :)