It would be nice to have one for the game Go as well, as a good teaching tool.
It's too easy.. Fiendish has way too many moves allowed. Many of the fiendish can be solved in 2-4 moves, out of more than 12. Also, the computer make stupid moves, almost begging to be beaten.
I really enjoyed this game it's good for giving the brain a slight workout!
The quantity of chess puzzles is fine, and chess is always good.
Unfortunately, the AI in place is so atrocious that you often don't need to see through to all the possible outs the opponent has; you set up some stupidly simple trap and the AI just blunders right into it for a mate in two when it should take several moves more than that.
Including the option to play against the AI in a normal game of chess just makes the core failure more obvious. Also, something isn't right with the castling detection; it is often not possible to castle in cases where it should be.
Making a chess AI that sees through 6 moves into the future is a trivial task these days; failing to do so in a game which hinges on that level of accuracy is inexcusable.
even in fienddish level, the AI got caught in schoolarship mate (mate pastor in spanish), and much of the problems could be resolved in less moves than you suggest. that's why you get 2 stars, 3 picos.