Hi, The error you're getting is the following: java.lang.NullPointerException at greenfoot.util.GraphicsUtilities.toCompatibleImage(GraphicsUtilities.java:218) at greenfoot.util.GraphicsUtilities.loadCompatibleImage(GraphicsUtilities.java:200) at greenfoot.GreenfootImage.loadURL(GreenfootImage.java:119) at greenfoot.GreenfootImage.loadFile(GreenfootImage.java:143) at greenfoot.GreenfootImage.<init>(GreenfootImage.java:69) at greenfoot.Actor.setImage(Actor.java:306) at Paul.checkKeys(Paul.java:74) at Paul.act(Paul.java:36) at greenfoot.core.Simulation.runOneLoop(Simulation.java:167) at greenfoot.core.Simulation.run(Simulation.java:108) Basically, check what you're doing on line 74 of Paul.java. Are you using the right case for specifying the image names? And have you uploaded all the images correctly (put them in the images folder?) For us to help you more, you'll need to upload the source so we can have a look at it! Just update the scenario with the "publish source" checkbox checked. Michael

Much better with the instructions! It's still a bit big (tall) though, it's probably worth shrinking it a bit. I also stumbled across this whilst playing: java.lang.IllegalStateException: The actor has not been inserted into a world so it has no location yet. You might want to look at the method addedToWorld on the Actor class. at greenfoot.Actor.failIfNotInWorld(Actor.java:620) at greenfoot.Actor.getX(Actor.java:139) at Timer.act(Timer.java:47) at greenfoot.core.Simulation.runOneLoop(Simulation.java:288) at greenfoot.core.Simulation.run(Simulation.java:158)

I've had that a couple of times too, but I still can't find a way to reproduce the bugs reliably... until then it's quite hard to work out why they're being caused!

Ooh I like this! Nice take on the original. My only complaint is that it gets quite hard quite quickly - any chance of starting off a bit slower / easier?