Its changed but to be honest i dont know how i did it and i'd like to change it. If you dont understand what i mean i made an image to explain it better

You can change the icon (favicon) of a game on its Edit Theme page. In this case, http://www.speedrun.com/edittheme/Project_M

I tried to change it but it dosent seem to work, the image its 64x64 and its this one

Make sure you ctrl+f5 after changing the favicon, sometimes that's all it needs :)

If it doesn't work, maybe the problem comes from the server.

I waited for an hour and now its fixed, thanks everyone :)