And note that they're all human. anything that dies in Disney movies is of somewhat realistic origin as opposed to the Mouse.
This is not a very logical conclusion. as I and some others have pointed out, the number of hits the characters take in game is not really canon. In Cutscenes, with or without an accompanying battle it's either slash n'block or a character is weakened by as little as one hit. Just like in a movie or TV show, and let's face it Square doesnt normally give a story explanation for anything except that absolute biggest gameplay elements and in KH1 and BBS, there were in-character references to gummi controls and save points.
Ultimately what I've thought about is this quite largely *in addition to* all the stuff we know about the Human body. The series tries to deal with existence, adding four simple concepts of what makes a human or a living thing to what we already know. Really, the only things about the heart, soul, body and mind as portrayed in KH is that, however absurd as it may seem, they are these fantastical elements to life that are somehow forever beyond our ability to grasp aside from a few impulses and wires.
to be fair, timmy was probably referring to most (Nickelodeon) children's entertainment and a much simpler type of game. Did anything bad ever happen to Mario or Sonic?