Yeah, I love the decorated whale! The scene is really cool and dynamic. I'm not sure if what you have right now is the final product or not, but my main feedback is that the image feels very modern/digital. It needs to be worn down and simplified quite a bit, given the look of painted wood (some of photoshop's blending modes may help with this). One other thing I'd suggest is modifying the painting, and doing this with future murals, to use only a small palette of muted colors (perhaps using irl medieval paintings to choose colors from) and then trying to stick to those colors for all of the murals. For the sake of consistency it's probably best to choose a palette which meshes well with the greens, cyans, and browns in the hall. Lastly, make sure to add some shadows and shading around the borders of the mural to make the mural seem embedded in the wall.