You should inform them about their vulnerability. Then he'll probably give you the game free.
It isn't a vulnerability...
He has already given the game to everyone for free. He did this by making it available and completely unprotected, your computer likely already downloads it when you play it. Open the page and perform a search for Slime.class on your own computer and you'll likely find it - although it may even be renamed to something else and sitting in your temporary internet files folder.
The fact that the browser isn't downloading it by default is likely a simple MIME issue or something like that.
Point being, the file is already being provided unprotected on the internet.
My program performs NO magic, this is NOT A HACK - It simply removes ANY restrictions on downloading a URL from the program used to connect to the URL. If you have READ access to the file, then you can download it by providing the URL. As another example, this program WILL download PHP files - BUT ONLY AFTER the server has compiled the finished view of the script. Therefore, it's still performing the same as it normally would - I would NOT get the actual PHP script, just the output it produces.
REPEAT - THIS IS NOT A HACK - What you CANNOT do is modify the game or claim it as your own...

-- Mon Feb 21, 2009 11:59 pm --
Time passes.... passes.... A few PM's are sent - And more time passes... Oooh - Look at that???
-- Mon Feb 23, 2009 5:35 pm --
PM from tomthecool:
Using your program, all I get is the .class file which actually just contains HTML code for the web page saying "this file does not exist".
Are you sure it actually worked for you? Could you not just send me the file if it did, since nothing at all seems to be going right for me?
Wow, you're right - I never looked at the file myself, just attempted a download of it.
I can tell you this - In order to run your game you need either a Java engine to run the .class file or you need an additional web page that loads the .class file for you (an example of this is the link to the game). I have NO IDEA why the .class file contains HTML. The .class file IS the game.
I've never seen this before - My guess is that it's something server side - I briefly followed the code and am quite stumped, they either implemented some weird trick or there's some type of security being implemented here that I've never seen. I'm an excellent programmer, but I never use java, I hate it actually, but have used it to some extent in college - I would recommend getting someone REALLY competent with Java to assist you at this point. My program acted the same way with this game as it does with a .php script -Why it produced HTML code is beyond me though - It's likely the same reason why when you try to go the that URL it re-directs you back to the page again - Like I said, some kind of server side security... It's probably the way the java class was programmed - I think the game itself is detecting that it isn't being accessed properly and re-directs???
BTW, given this new info - I'm gonna have to take back what I said - I SERIOUSLY doubt it's legal to have the game anymore...
Sorry for your luck, like I said contact a Java programmer for further (and more accurate) information... You DO NOT have access to the file, it's been hidden somehow - and therefore NOT free for home use.
However, this has CERTAINLY intrigued my 'as of yet' useless notions of Java... I still hate the way the libraries work, yet somehow hate the whole project a little less now...
Sorry I couldn't help more - But good luck!