I am a hardcore gamer at core. Once I have found a game to grind, I will play it until I can't overcome my limit.
The harder, the better.

Here is a non-exhaustive list of what I have done in the past.

Indie games

Open Hexagon by Vittorio Romeo
Quadruple world champion.

Super Meat Boy by Edmund McMillen and Tommy Refenes
106%.

Plague Inc.: Evolved by Ndemic Creations
Fully Evolved.
Speedrun top world scores.

Terraria by Re-Logic
Expert and Master Moon Lord solo mode.

FPS

S.T.A.L.K.E.R. Misery ver. 2.1.1 by GSC Game World and Misery Development Ltd.
Completed a playthrough with every classes.

Sniper Elite 4 by Rebellion Developments
Completed an Authentic plus campaign (one player) without any save.

DOOM Eternal by id Software
Completed Campaign, both DLCs and Master Super Gore Nest on Ultra Nightmare.

Stalker Anomaly ver. 1.5.1 by Anomaly Dev Team
Invictus+Completionist save complete.

MMORPG
World of Warcraft by Blizzard Entertainment
#8 FR Warrior
#1 Warrior on Les-Sentinelles EU
#8 Alliance Warrior DPS (worldwide) in the Damage Proving Grounds Endless.
#4 Alliance Warrior Tank (worldwide) in the Tank Proving Grounds Endless.

-----------
Steam Curator alongside the Challenge Enthusiasts and masochist.me
Member of the Winter Clan.
Former Millenium/MGG publisher.
-----------