Uhm, looks like a nice start. I few suggestions:
- Choose one genre and stay close to it. Meaning don't mix wooden segments with sci-fi platforms for example. It doesn't look believable.
- Don't give your rooms lights that have no logical light source. So, if you place a light, then add a light entity that provides the light.
- Try building your test game at least on mid lightmapping quality in order to receive shadows. They are an important part of your level design, you can make nice effects playing with shadows with really no effort.
I love the light colour of screen 1 (latest).