Ok, so I did enable developer mode and get terminal there. After fiddling a while with the codes you guys gave me, it seems there is nothing really out of the ordinary in the used space. I mean, the games do take up space, but uninstalling them frees up space in the area denominated "Installed apps". "Application data" still remains in 2,0/2,1Gb. The only thing that so far seems to bring it down (just a little bit) is clearing web browsing data.

I've found a few other discussions where other people had the same problem, but didn't really find many definitive solutions... I guess I'll back everything up and make a factory reset, but for what I've seen in those forums, it's not likely that will help.

Just wondering, any chance that there would data cached somewhere after every connection to a computer in mass mode for data transfer? And while I'm there, is there any way to get access to restricted folders. Also, where does the stuff downloaded from Nokia store go? I downloaded a ringtone some time ago that I don't like and want to get rid of it, but I can't find it in the same folder where all default ringtones are.