This is one of the best sudoku programs out there for the 83+/84+ series. It has a REAL gui (yes, it really is a GRAPHICAL user interface), virtually an unlimited number of puzzles (1,000,000 to be exact), 5 different levels, and a save feature-very useful:).

However, there are two things I find annoying. One, it doesn't distinguish between the given and the inputted numbers, so sometimes you delete a number that was part of the original puzzle. The hint system, although very nice, does not make sense. The harder levels have less hints than the easier ones??? I think it should be the other way around! But then again, some people like this system. Also, it can easily be fixed by modifying a few lines of the program.