I was thinking to make my arcade game match the players strength in the hard level mode. Like checking the score and if the human player's score is above computer's for certain number of units then the computer player would automatically increase the speed of its reactions, just like a human companion who gets more determined to fight back.
Does this sound a good idea to you? Are there other ways to approach this, so to make a game, like air hockey for a crude example, permanently challenging for anybody?
EDIT: I agree with the answers below. I believe that most people like to win about 70% time over the computer in order to be motivated. Hence an adaptive intelligence must not be become too superior to the player and depending on human player's concentration and some random elements in the game (good 'old' quantum RND), the outcome should be always uncertain.
A nice thing about this is that such a system could handle week and strong players and would adjust to the human's learing curve.