And how to move to another if its necessary?
Because Im Game Maker user for me every thing which looks like a blank square shape is a room. <img src="smileys/smiley4.gif" border="0" align="middle" />
Yup, a room. You can change layout with system action (look in the System object).
Develop games in your browser. Powerful, performant & highly capable.
And how big can be one room?