What Defines Successful Game Characters?

Thanks to TotalGames.net for their feature discussing what makes a videogame character popular. They point out that "almost every character-led game will see a significant chunk of development time spent honing, adjusting and, in some cases, scrapping characters", and discuss Link's famous make-over for Zelda: The Wind Waker, saying "...the outcry that greeted this graphical overhaul underlines just how important game characters are to players." However, the piece concludes: "But for every ignored genius, there are hundreds of mediocre and downright irritating game icons lurking on the shelves", citing Ty the Tasmanian Tiger and the Poochy-like Bitmap Kid as examples of the bad in character design.