I feel like the lighting is extremly hard to get right. First of all i cant properly get rays without making the scene too dense, and i also cant seem to get the scene lighter without removing the depth or making the contrast too high, which means it will be very dark when viewed on smaller devices such as phones…
Lighting definitely is a harder element to get right. Looking at it, I’d say the silhouette of the figure and piano(that is a piano right?) need some sort of rim light to make them stand out. With the moon and window more light could be emitted from those directions.
I am not a professional when it comes to light. But I feel like I know what looks good in an image anyway, and usually my light is cheated in a way to make things look nice. I use multiple layers and have my lights affect only certain layers to achieve a specific look. It’s not necessarily natural lighting, but I have control over how things look.
I don’t know if that was helpful at all, or the type of critique you wanted. 
Its good critique and i appreciate it very much! i dont really know how to make light affect only a certain layer and i also dont know how to render different layers in compositor as i dont understand any of the tutorials, however 
the moon as light source feels artificial (like a lamp), the highlighted floor is too warm (yellow to read) while it’s expected to be cold (blue to violet range). i suggest to try making the moon light color a bit blue-ish. using some night scene references should be helpful
Do you mean under the piano? I cound cramp that down but the moonlight is white-blue unless you have nightmode on a phone for example.
I don’t know how to fix the artifical moonlight, though i could add a lantern on the left side, i just fear it will remove the depth and focus, as well as remove shadows.
