Basic idea, but competently executed and *bloody hard*.
I could only get up to four colours on 3x3 and two on 5x5 - I ended up cheating with the print screen tool to get the rest of the medals.

Audio is kinda jank, too - a couple sound effects seem to be cut short.

I can take a screenshot hahahahahahahahaha

it goes to a grey screen when I finish a level...

Ok, I mean the later levels are pretty much impossible unless you have a photographic memory. I just screen shotted every level before playing and used the screenshot to win, just so I can get the medals, which is obviously an extremely boring way to play. Good idea but not very well executed.

There's a very bad bug in this.

If you start from the very beginning and play the levels sequentially, you won't be able to play the last few levels at all and you'll need to either clear browser cache and play again, this time starting from the end going backwards *or* start again in another browser, again from the end going backwards (just to be sure)

What happens is, if you play it sequentially, the later levels start disappearing from the level select altogether as you start clearing stages.

That is an extremely frustrating bug!