Your object is to escape the room. In order to do so, you have to get the
keycard inside the firebox. But to open the firebox you need something to break
the glass and so on and so on.
In the lower part of the screen your inventory is shown, you can pick up some
items in the room for later use.
Click on an item in your inventory to put it in the use slot (lower righthand corner) and then click on an item in the room to
try to combine them.
The top part of the screen shows information about items and your actions. Good
luck!
You are able to fly/walk in the room using the arrow keys.
You can pan up and down with the mouse-scrollwheel and you can click on items when there is a hand pointer over it, with the left mousebutton.