I think that's what trophies like 'Foxiest of the Hounds' (read. Deus Ex Human Revolution) are made for. Conviction is not an exception. If you want a challenge - here it is in the Difficulty settings/trophy and achievements list. I've found Splinter Cell Conviction was a real challenging and yet rewarding game if played on hardest difficulty.

DmC on PC = 60 fps, highest quality anti-aliasing all the way.