(First time on Greenfoot in months and months and months!) I haven't looked over the source code, but from what SPower said I'm assuming you're storing a value for pi. You can actually just use Math.PI :) http://docs.oracle.com/javase/6/docs/api/java/lang/Math.html#PI

Oh fair enough. By the way, if you're ever stuck, I don't mind helping :) I haven't coded java in a while but I know enough to probably be able to help with anything you need. I really like the graphics of this game, it feels very clean - I'm looking forward to it becoming playable :D

If it helps, its running perfectly for me, but then I have a decent computer (in relation to "Might be a memory leak somewhere, or just might bad computer.")

Nice :) A couple things could be fixed though: (1) This is purely a graphical thing, but a ball 'blows up' it seems to flash big for an act() frame before going small and growing (hard to explain, but you can probably see what I mean from playing) (2) This second one was a problem I encountered when making http://www.greenfoot.org/scenarios/4716 (my version of the game) when the moving balls are doing collision detection, they treat the large circles like squares (presumably you're using getOneIntersectingObject(...), and that just treats the image as a square, regardless of transparency). The problem this causes is that they can hit nothing and blow up.. I'll let you dream up and code the solution, but a clue that might start you off might be to incorporate getObjectsInRange(...) somehow. Like I said though, I won't say more than that for now

Out of interest, was the issue with the arrow that the pointer was static? That screwed me up early on in using Greenfoot - when you press reset, it doesn't reset the static variables, unless you specifically do it in a constructor/method. Then again, its quite useful for session high scores (without use of UserInfo, which I still haven't got round to ever using)