The mentally disabled are a group who deserve linguistic sympathy. If you'd said the game design was 'gay' and been called out on it, would you grasp why it was wrong? Or been racially offensive about Begians?
Most of my friends are gay and they do not mind someone using the term gay as an insult. I'm being told by one of them RIGHT NOW that it may be the same word, but a different definition is being used, just like gay used to mean happy. My wife was blind, and she loved a good blind joke and cracked blind jokes all the time. Honestly, the vast majority of people who could be considered disabled DO NOT want their hand held and to be treated as delicate and different from everyone else.
It's all about context, and if there was any intent to actively offend the group in question.
