Another Crab's Treasure -- All Achievements
Bad North: Jotunn Edition -- All Achievements
Batman: Arkham Asylum (GOTY Edition) -- All Achievements
Blasphemous -- All achievements
Carrion -- All achievements
The Case of the Golden Idol (+2 DLC) -- All achievements, all clues, all scrolls, epilogue complete
Chibi Robo! Plug Into Adventure! (GameCube) -- All Stickers
The Children of Clay -- All achievements
Cuphead (+ DLC) -- All S & P ranks, all achievements
Helltaker (+ DLC) -- All Achievements
Is This Seat Taken? -- All Achievements
Luigi's Mansion (GameCube) -- All portrait ghosts, all Boos, Rank A obtained, Hidden Mansion complete
Luigi’s Mansion 2 HD (Switch) (Single-player) -- All Boos, all gems, all 3-star ranks, all upgrades (I can’t access multiplayer so give me a break here)
Nodebuster -- All Achievements, all milestones
Papers, Please -- All achievements, all endings
Pikmin (GameCube) -- All ship parts, all bosses & secret bosses
Pikmin 2 (GameCube) -- All treasures, all bosses, completed piklopedia, completed all challenge levels while collecting every treasure and bug body without any pikmin dying
Pikmin 4 (Switch) -- All treasures, All (non-infinite) missions, all upgrades, all castaways, all cures, all platinum dandori medals, all onions/flarlic, Olimar's Story 100% complete (all ship parts, all onions, all flarlic)
Pizza Tower -- All P Ranks, All Achievements, All outfits, John approved (ALL DONE AS BOTH PEPPINO AND THE NOISE)
Resident Evil 4 (2005) -- All Achievements, All Blue Medallions, All Bottlecaps, Separate Ways Complete, Assignment Ada Complete, The Mercenaries: All 5-star ranks with all characters
Robocop: Rogue City -- All achievements
Rodland of Pipes -- All Pipes complete (including classified pipes), all Flyers, all Incident Reports
Spyro the Dragon (Switch) -- All dragons, all eggs, all gems, all skill points
Super Mario 64 (Switch) -- 120 Power Stars
Super Mario Galaxy (Switch) 121 Power Stars (as both Mario and Luigi)
Super Mario Sunshine (GameCube) -- 120 Shine Sprites & defeated Bowser
Super Mario Bros. Wonder (Switch) -- All medals (all Wonder Seeds, 10-Coins, Gold Flags, Badges, and Standees)
Super Smash Bros. Ultimate: World of Light (Switch) -- All story mode content

Total so far: 23 (+ 4 DLC)

Ones I'm interested in:
-Cave Story
-Last Call BBS
-UFO 50(?)
-We Love Katamari REROLL+ Royal Reverie
-Binding of Isaac
-Dicey Dungeons
-Hotline Miami
-Signalis(?)