The bottom image is very flat, it looks like a solid flat wall rather than a room the character can stand in, because the values of the front wall and the back wall are so similar. Something more like the top image, where the back wall is darker would work better, since both the front walls (floor/ceiling) and the character stand out well against it.
The tiles feel very noisy, they give me a bit of a PS1-era look where they'd downsample photo textures. It looks lazy, to be honest ): I think these would benefit a lot from some clean-up and simplification to match the character's cartoonier style.