The last few levels were rubbish yeah, there was a bit near the end that was quite good though but the half hour or so of gameplay upto that and everything after that felt it had been slapped in for the sake of it.
Personally never found it that difficult though - aside from getting to grips with it at the first camp and a couple of bits near the end (Volcano bit) don't think I had to redo any bits due to dying.
EDIT: Though I think some people went the way that wasn't supposed to be done but are more obvious which are intended to be impossibly difficult as you aren't supposed to go that way - when there are i.e. overhead walkways, etc. that are the intended route that aren't as hard.
Personally never found it that difficult though - aside from getting to grips with it at the first camp and a couple of bits near the end (Volcano bit) don't think I had to redo any bits due to dying.
EDIT: Though I think some people went the way that wasn't supposed to be done but are more obvious which are intended to be impossibly difficult as you aren't supposed to go that way - when there are i.e. overhead walkways, etc. that are the intended route that aren't as hard.