Lemmings doodle pad

This is a little Java applet that I wrote while teaching myself Java.  Three Lemmings wander around, and by drawing on the screen with the mouse you can make ramps and things for them to walk up.  Right-clicking on the screen works like an eraser. Click Here to start the applet. There are two versions of the doodle pad, as different web browsers seem to need different things, so click here if the main version doesn't work!

The applet works quite well usually, but does tend to use up a lot of CPU cycles.  Also, if you reload it too many times the image of the lemming walking from left to right sometimes mysteriously vanishes!  I've not got a clue why though!