We've added World edges and the current map is 200m x 200m, which is about the same size as a normal city block in Manhattan. The map size depends on scenario settings, but we expect that most scenarios will have similar sizes. It's possible to build below the ground and there will be some rooms that must be placed underground. Buildings doesn't have to look like towers as the picture illustrates, but we will implement that people are being more happy if they manage to get some daylight from windows, etc, so you might not want to build rooms without windows.
First image of the GUI. We have not decided the final layout of the GUI yet, but this is the current default view. You have the time and game speed lower to the left. There are 5 different game speeds that you may choose from: pause, slow, normal, fast, very fast and light speed. We currently having a 3 day week, 1 week per month in the game calendar and the minimum time unit is 1 minute, so months should pass by quite quickly.
You may select room categories to build rooms from in the lower center area or expand the lobby. Rooms are always placed in the lobby. All the categories are dynamic it's possible to add other classes when writing mods to the game. We still need to add spaces in the GUI for economy, population, star-rating, achievements and statistics.
This picture describes how lobby is constructed. You simply select the lobby builder and drag out the area where you want to build your lobby. It requires that the new lobby is connected to the building. You need to have something tiles built below when constructing above ground floor.
The following picture describes how to place rooms. We've decided to place predefined rooms since it will too much micromanagement to build a complete skyscraper with 200+ floors if you should place each window, door, toilet, etc. The right area describes the figure of the room. We will add arrows that indicate which side that must have free space towards the lobby. Rooms must always have access to the lobby.