Shin Megami Tensei series.
- Hey if you imagined Dark Souls 1 and 2 was so hard to play, ATLUS was already best friends with Tecmo when it comes to games with hard difficulty enforced in Normal Mode. Major laugh is that Dark Souls never have easy mode. I recall playing that game so many times to perfect it without dying just once or to any boss fights.
- Shin Megami Tensei III: Nocturne is the pinnacle example of hard games in ATLUS work. Everything is unfair in Nocturne and let's just say, all of the boss fights are more than hard. Anyone who knows the dreaded Matador and got their butt served to him tells you that you should be ready to deal bosses LIKE HIM AND HE'S GONNA TEACH YOU THE IMPORTANCE OF BUFFS!
- Shin Megami Tensei: Strange Journey is Nocturne; only a lot harder. With new status ailments, you don't want the MC to be always be the prime target of those new status ailments since it automatically calls game over when the MC is eliminated. I even recall THAT one place I hate so much until now.
One place contains Poison Panels and Teleport Pads, to make it worst; there's no idea where the teleport pad will travel next telling you to use a guide to figure your way out. Did we mention someone has a sidequest for you IN THE MIDDLE OF THE POISON-TP PANEL PLACE? GOOD LUCK FINDING HIM THOUGH.
- Shin Megami Tensei: Digital Devil Saga Tuner 1: OH DEAR LORD. I keep replaying this game because I've beaten the undefeated Hito-Shura once and if I want to do second run against him, my nerves needs more relaxation. This Hito-Shura from SMT3: Nocturne is the prime example of hidden boss fight. He's deadly and all of his skills are capabale of debuffing while dealing huge amount of damage. Did we mention he was the foundation where Elizabeth, Margaret and Theodore came from? Really, those who beaten the three hidden boss (Elizabeth, Margaret, and Theodore) cannot imagine how to deal Hito-Shura himself who is broken in complete ways and anti-cheat proof.