I'd like to see a version that allows you to have it be a code with a different number of possible colors than just 6. Like have you increase the number of colors to choose from up to maybe 10 colors. Or maybe it's allowed to lie about one color in the combination, for one of your guesses, and you have to account for it and figure out where the lie is. Or only give you incomplete information, for it to not tell you if one of them is in the right position or not, or for it to tell you that you have either 1 or 2 correct colors, but you don't know whether it's 1 or 2. Because let's face it, 10 turns this way is totally excessive. There is absolutely no way to play under any constraints that make this game interesting this way, you can't help but narrow the 1296 possible combinations down to 1 and win on like the 6th turn no matter what it is. I tried constraining myself to always use 3 of one color and 1 of another every turn, plus never to use white, until I determined the combination, and only then was I allowed to use white or something other than 3 of one color and 1 of another, and I still won in 7 turns or less 4 times in a row, I tried making 9 completely random guesses with no sense behind them for 9 turns and then I have to figure it out based on the results of those 9 returned results what it is for the 10th, you just can't make it fun or challenging this way, it's easy and it all just falls into place no matter what you do.
I also don't like the dragging of the circles, I like the mastermind game implementation from the-swain that's only on armorgames now a lot more, where you just click on the colors you want for the positions you want rather than dragging them.
But hey, it works. My computer started using tremendous amounts of processing power in the middle and it was a pain but I'm not sure it was this game that did that to it. Also the sound control would NOT let my mouse let go of it and it would not let me pick up a circle for over a minute. At VERY LEAST, it should NOT go back to full volume at the end of every game if the user set down the volume, it should retain the value the user set.