The one game that I always used to use as an example of a ridiculously unplayable game was Obliterator. The guy in the game was totally sluggish and unresponsive and you had to use the row of big onscreen icons to control him. It's easy to run into walls or end up facing the wrong way or perform some other stupid action. You have no chance unless you rehearse the action over and over again. I haven't played it in years but the memories remain.
