Make A Sudoku Solver more interesting

[Sid123]

Hi, so I am writing a sudoku solver where the user can enter their puzzle and the program will solve it. Code +algorithms for this are all over the internet, and regardless of whether I use them, this kind of takes the fun out of it for me. Any ideas of any similar projects that I could do that aren'r quite so widely done, I am enjoying the idea behind it(how feasible is a crossword solver)? OR anyone got any suggestions of how to make the solver more interesting?
So for example I was thinking it can reveal the value of certain squares individually if required. I was also wonderig if anyone knew(from a high level perspective- I want to write the code myself) how I could vary the difficulty of sudoku problems generated

[MiiNiPaa]

I was also wonderig if anyone knew(from a high level perspective- I want to write the code myself) how I could vary the difficulty of sudoku problems generated

Less cues + larger no-hints areas = harder sudoku. You might be interested in these articles:
http://www.i-programmer.info/news/181-algorithms/4598-the-chaos-within-sudoku-a-richter-scale.html
https://en.wikipedia.org/wiki/Mathematics_of_Sudoku#Constraints_of_Clue_Geometry

(how feasible is a crossword solver)?

It is pretty easy as long as you would just create potential solutions for given grid. If you will try to analyse questions it is way higher level. I have only seen IBMs Watson to actually do the task of answering questions given in natural language with worthwhile accuracy.

[Sid123]

Anyone got any other potential interesting intermediate level projects ideas?