The fades are performed by pre-calculating a look-up table of images. Each one is a copy of the original image (a ghost or diamond) but with an added alpha value for each of it's pixels (from 0 to 255). I only make around 10 to 20 faded copies of an image based on how fast I want the fade to be (a fast fade uses less images then a slow fade). This way I make as few images as possible and so use less memory. Then the Ghost or Diamond just selects which image to use depending on how it's currently faded (or if it's fading at all).

i love it! it is kinda like my game but mine has horses.... um how do you make an actor eat a food? How do you put ur game on here and other websites?

There is already a place to ask general questions about Greenfoot: http://groups.google.com/group/greenfoot-discuss In the future it would be probably best to ask there, especially if you want a response as it's more likely to be read. Anywho, in order to upload you need to click on the File menu and then Export in the Greenfoot editor. You should also be using the latest version of Greenfoot. To make actors eat food, in the actor that's eating you check for an intersection with you food object with the getOneIntersectingObject method (i.e. getOneIntersectingObject(Food.class) if your food class is called Food). It returns null if a Food is not found, or a Food object if one is. If it did return a Food object then just remove it from the world (i.e. getWorld().removeObject(food)) and then do whatever happens when you've eaten food (like scoring some points). There are also resources on the www.Greenfoot.org site that should also be able to help.

Impressive game... although not very complex it provides a fair amount of entertainment as the difficulty increases. (My first score was 123)

If your open to suggestions, a nice background song would be twilight techno - dimrain47. I used it in a scenario similar to this one, called bouncy. If you wish, you can take it out of there.