Battle Sudoku!

I've downloaded Visual C# Studio and I'm working on programming a game called Battle Sudoku. It's like Sudoku, except multiplayer, and whenever you complete a row, column, or square you'll gain power to hit your opponent with something nasty. It might rotate their board, flip it, or replace the numbers with different shapes, or something even meaner.

Microsoft is setting up this neat thing going where if you join a creator's club you can self-publish games on Xbox Live community games. You can even make money off of it. It has to pass peer review in order to be published to make sure it is bug free and content appropriate. If I get this thing working I might shell out the cash to get an Xbox 360 (necessary to submit the game) and the $100 for the creator club membership. Who knows, I might make a small profit.

Programming the game is very interesting. I have to write a program that is able to solve the puzzles and record the steps taken in solving the puzzle (for realistic AI). It also has to be able to generate puzzles according to difficulty. This means I have to learn Sudoku solving techniques in order to program the game. I'm learning all about naked and hidden quads, along with Swordfish, Jellyfish, XWings, and locked candidates. I completed a lot of code today, and I'm confidant I can get it do what I want. However, I am a bit worried about the efficiancy of my program; whether or not it can generate a puzzle and solution in a short amount of time. I've also been pondering about what options I could add. Anyone up for a 25X25 SuperDoku? Or for those less adept at puzzles, perhaps I could add a 4X4 and a 6X6 option.