Puzzle Quest
This game works because it make playing Bejeweled even more fun to play. The reason why is because that the game mechanic gives you a reward for playing the game, you don't just play the game to go to the next level, you actually get rewarded for it like getting gold, experience points, and it also gives you an incentive to collect certain rows of three. Also the game also encourages the player to collect gold buy building ones own players sanctuary. That alone will give a materialistic person like myself a reason to play. The story element associated with that is a nice touch and helps the game become immersive rather than just playing a puzzle game like Bejeweled, also it makes playing the puzzle game more engaging by having you compete against the computer in a battle.
The game doesn't work in that it is too much like Bejeweled, there needs to be a new way to play the game and come up with a brand new unique puzzle to play against the rival. Also the avatars and characters in the game are not unique and the game mechanic doesn't let you design your own character. The game doesn't let you decide which side of good or evil you want to be on, you are automatically placed on the good side, though the player may want to join the dark side but the game does not provide such an option.
A different theme could be the ever so popular fantasy theme and that could be changed with a mere skin change. Avatars would have different clothing and the wizard avatars would be a more advanced wizard (i.e. sorcerer.) Especially gaining mana for spells which is already a game mechanic is very fantasy immersive for the player engaging in the game and would have a more immersive feel while playing it.