I'm just going through all the reviews I got, I was a bit busy the last days.
Basically: You're right with every point.
And yes, I want to expand it, next step is different colors and walls, then maybe prisms and lenses as you said.
Oh, the blurryness I have to check more indepth. I'm not familiar with shipping a game yet, so maybe I did some resolutions mistakes there. Will try it on a smaller screen if I get the chance.
Thanks for your feedback!