you should make it so that the asteriods keep spawning by putting a similar generation code into the act method and you should make the initail asteroids only spawn farther forward than you ships location so you can't spawn in an instant death trap. One last thing when the asteroid kills you should put Greenfoot.stop() on the next line so it stops.
Cool secopnd game though. I'm playing your first now.
2012/7/14
2012/7/14
2012/7/14
2012/7/14