I might be going the wrong way with that then. Using stegoveritas I noticed that PNG has a bunch of "ISO-8859 text, with very long lines, with no line terminators" files which isn't normal for PNGs.
If you'd like to whine a bit with me, join me at:
##ctfcompetition @ freenode, I'm currently under the nick caulifl0wer
As the comment above implies, it seems like my approach was wrong and the answer is in one of the images I guess