This stopmotion is well made and thought out. I did think some of the jump-cuts were a little choppy, but overall the animation was well put together. I liked the concept of the claymation character altering its own little world.
In terms of improvements, I think you could try more gradual transitions when objects are added or removed. For instance, instead of things simply disappearing and reappearing over single frames, you could possibly make them shrink or grow. The sudden appearance and disappearance felt a little jarring.
Overall, nicely done. Keep it up!