+* [Example of an not-fully-immersive game](http://www.i-mockery.com/minimocks/50arcadecabinets/star-wars-arcade.gif)
+* [A more immersive game](http://upload.wikimedia.org/wikipedia/commons/7/78/AC89-0437-20_a.jpeg)
+
+
3. `callcc` was originally introduced in Scheme. There it's written `call/cc` and is an abbreviation of `call-with-current-continuation`. Instead of the somewhat bulky form:
(call/cc (lambda (k) ...))