I kinda get Record of Agarest War, though I kinda wonder why Guilty Gear wasn't mentioned, I-No anyone? But Deathsmiles? I've seen the dual endings for each character but outside of one simple bath scene I don't see how the game could be lumped in as a stepping stone for hentai porn. Duke Nukem 3D and The Saboteur are perhaps more blatant than any of those titles.
I would guess they're hacked because Illusion began programming their PC games to not work outside Japanese computer operating systems. Who knows what their reason is for that. Though you have to admit some of the 3D games they've produced do look pretty. How they play might be a different matter.