I actually just finished it on hard mode. It's honestly not that hard, especially if you remember that you can save your armor upgrades for boss fights since they give you full health.
The hardest parts are probably the two fights with two Titans and a bunch of mooks.
I'm still working on the combat/predator challenges. That's all I have left to 1000/1000 it, and it'll be my 10th retail game I've done that on. Luckily the difficulty on the combat challenges is always set to normal. They're still pretty tough to get good scores on, though.
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Gamertag-Murphiroth
Pokemon Black-1978-9490-1161