Hardcore mod adds new 6 difficulties which are makes Max Payne 2 game harder than usual. Enemy can kill you with 1-2 shots, you can't use slow motion (only in hardest difficulties).
Max dies in 1-3 hits, NO bulletime and bullettime-shotdodges. It's the last 3 difficulties - Legendary Detective, Hell or Heaven and Revengeance.
If you beat the game on Revengeance difficulty - I'll say that you're really badass!