Looks good so far - Main issue is exporting - It doesn't automatically save it as an image, I had to manually put in .jpg into the file name and even then the floor is bleached out.
Also finding the save wasn't intuitive - I didn't know I had to press escape to bring up the menu.
I love the style - I'd like the option to scale some item - eg I'd like the options for smaller beds and larger rocks if I could choose the scale.
I'm sure I'll have some more comments at a later stage, but these are my thoughts after 10 mins of play. Great start though.