I did a blog on a difficult game on my website (the address to it is in the fish tycoon guide section) and found it to be quite a bit harder when it came to keeping the fish healthy! It started out about the same, but the further along I went the more illnesses the fish caught. LOTS of money was needed to keep them healthy! Quite a challange to keep up with the meds. There may be other differences, too, but that's what I noticed.