Still to this very day that ranger mode is available as paid DLC. I still don't understand, who would pay money for a difficulty level ?!

For me, maybe Enter the Gungeon. Although, technically speaking, I have not managed to defeat Bullet Hell yet.

I've also beaten all the Souls games and Bloodborne.

Super Mario Bros. The Lost Levels - the orginal game, not the All Stars port.

That's the version that had a map where you could repeatedly enter the wrong pipeline and the game would repeatedly kick you back to the start of the level while the clock was still ticking down, right?

DKCTF

Yep.

Hmmm, going by the game that was hardest to platinum due to chezzy AI I would say God Of War 3 followed by COD:World at War

Amen.

200% on Donkey Kong Tropical Freeze

I cannot believe NO one mentioned Demon's Souls, which knocks all the Souls games out of the park.

Imagine fighting EVERY single boss on half health, the first time you encounter them, that's what being hollow meant when that came out.

None of this namby pamby Dark Souls health scheme ;p