Try this online puzzle game

I don't see level 3. Could someone give me a hint?

I think the page title is a pretty good clue, that and the source hint.

Play around with the photo.

Help with 21!

I know it has do with light and that there is another darker cat et cetera, but I still don't see it. What do you mean with play around? I don't have to edit it, right?

You are on the right track, it is a song except sped up

Ya, edit it. open up photos(or whatever you have) and see if you get the bright idea.

I slowed it down but got nothing!

It's backwards isn't it?

Nope...I have it in audacity at the slowest tempo ever and all I hear is beeps...