Okay, you mentioned a "right mouse button" which means you're not running on a Mac, Tablet, or Android device. Which leaves PC or Linux.
Which is it?
We also need to know which version of the game you're playing, Humble Bundle, Mamba disk, etc.
Does anyone know how to change resolution/window mode without entering the game options?...I got a hunch.
Check out this thread:
http://forum.amanita-design.net/index.php?topic=499.msg2432#msg2432