this is the error: java.lang.NullPointerException at BeginWorld.textFieldIsDoneWithText(BeginWorld.java:128) at TextField.addInput(TextField.java:102) at TextField.act(TextField.java:93) at greenfoot.core.Simulation.actActor(Simulation.java:565) at greenfoot.core.Simulation.runOneLoop(Simulation.java:523) at greenfoot.core.Simulation.runContent(Simulation.java:213) at greenfoot.core.Simulation.run(Simulation.java:203)

you might want to make the world wider and make the patty move quicker. look at my game called zombie attack ,for some ideas, at this link: http://www.greenfoot.org/scenarios/4213

fixed the score problem. add this to the world class. public int timer =0; public void act(){ if(timer>=100){ score = getScore()+1; scorer.updateScore(score); timer =0; }else{timer++;} }