I don't really view balance in single player games any differently than I do a multiplayer game. A well balanced game has a wealth of options open that promotes

I don't really view balance in single player games any differently than I do a multiplayer game. A well balanced game has a wealth of options open that promotes dynamic gameplay. A poorly balanced game degenerates into stagnant gameplay because one or two options are much more powerful than the rest. A good example of a well balanced single player game is tetris. All the pieces are useful. It may be easier to complete a line with the straight piece, and in a tight pinch a less skilled player might hold out for it while placing down other pieces willy nilly, but if every piece was as easy to use as the straight piece then the game would have less variety and tension! At certain points in the game you may not want a straight piece because of the way you have laid down your previous pieces, the game is dynamic because the optimal strategy is changing all the time because of how you played the game, this adds even more strategy because you can also influence how the optimal strategy will change. A good example of a poorly balanced single player game is... well in my opinion most single player games are poorly balanced. Either the game is so easy that it really doesn't require you to strategize at all or the game is easily cheesed by using one overpowered technique. This is especially evident in many RPG's, although they try to hide it with a huge skill tree (of which almost invariably a large number of skills are useless and a couple are ridiculously overpowered) or by having you learn a whole bunch of enemy weaknesses and resistances (IMO this is cheating, the challenge isn't dynamic as these stats are unchanging and typically only serve as an overwrought color matching exercise). Pokemon is a good example of this, although you have hundreds of pokemon to collect and train and it seems a variety of enemy types should force you to have a varied party yourself, the easiest way to beat the game is to overlevel your starting pokemon by giving them all the experience points and grab one or two other pokemon along the way to cover your weaknesses in the end stages of the game and load up with necessary non-combat moves.