First of all you need to get your design right. This includes consistent linework and style, as well as keeping to some sort of a perspective. Whether you acknowledge it or not, there is perspective in the image. If there wasn't, it would either look totally abstract or like a 2-year-old drew it.
So you've got a messy style. That's no problem. But you stray from your style on some parts. For example, everything is outlined with thick black, but you've decided to outline the blanket with red and you've decided not to outline the bulletin board at all. Also, you're line size is consistent, except for the lamp. In addition, the texts don't work with your style. You should rather just draw the texts. The perspective is correct for the most part. But once you have a perspective, you should stick to it. The table and the chair aren't in perspective with the other elements in the image.
Now once you got design covered, you should think about the outlook. What are you shooting for and what style best enhances the purpose? The thick outlines are a negative for me. If you'd just half the size of your brush, you'd be getting a much better outlook automatically. Using black lines is ok, but you gotta be consistent with it. If I was you and I wanted outlines, I'd use darker color outlines, meaning a darker color from the fill color. Shadowing is also a great way to add depth and make the outlook much much better. You should try it. Anyways, your style is your style. You don't need to pander to anyone else's opinion. But I think we can both agree that a more appealing outlook expands the audience.
I did a one-hour paintover. I basically redid everything:
- Corrected the size to 640x480.
- Smoothed some of the angles and made it using fill vectors.
- Tried another approach by doing only fills without outlines.
- Corrected some of the perspective problems.
- Increased the walkable area.
- Balanced the colors out a bit.
- Added shadowing.
- Moved the window lower.
- A lot of other stuff.
- I left some of the more detailed objects out.
Don't get offended or anything. I just wanted you to see how much more appealing it could look, if you payed a little more attention to the style and design. This is a totally different approach and I know I kinda went into extremes. I have a habit of doing that. I just can't stop if it isn't to my satisfaction.