I have an achievement for Wins, but not for Total Games Played, because having both inevitably makes the ratio important, and that’s not the point.
These achievements are meant to not be dependent on specific features of tiers, so we don’t have to update everything if e.g. Pheromosa gets banned from OU or the generation changes.
Everything is “on the ladder” because I don’t want to bring about challenge spam.
For situational and handicap achievements, I tried to prevent chasers/opponents from being too miserable, and didn't want to encourage people from arranging ladder battles with their friends to "boost" achievements. That’s why there aren’t achievements like “win a 500 turn battle”, “have this very obscure situation you could just plan out instead”, or “have this situation reliant on the opponent doing or bringing something unusual”.
Fight Me: Play a battle.
Triumphant II, III...: Win (1, 5, 10, 25, 50, 100, 150, 200, 250) battles on the ladder.
Exalted II, III...: Win (500, 1000, 1500, 2000, 2500… 10000) battles on the ladder.
Streaker II, III...: Win (2, 3, 4, 5, 6, 7, 8, 9, 10) games in a row on the ladder.
Uncontested II, III...: Win (15, 20, 25, 30, 35, 40, 45, 50) games in a row on the ladder.
Elite Streak II, III...: Win (2, 3, 4, 5, 6, 7, 8, 9, 10) games in a row, and both start and end this streak in a ladder’s top 500.
Looking Up II, III…: Reach Top 500 on (1, 2, 3…) ladders. (it ideally would say which)
Golden II, III…: Reach #1 on (1, 2, 3…) ladders. (it ideally would say which)
Perennial II, III…: Be #1 on the same ladder in (1, 2, 3…) different months.
There Can Only Be One!: Win a tournament in a public room.
RBTT Winner: Win the Random Battles Team Tournament.
TLT Winner: Win the Tours’ Leaderboard Tournament.
Come On!: Miss a move with at least 90% accuracy on the ladder.
This Is Fine: Hit a move with less than 80% accuracy three times in a row on the ladder.
Nifty!: Activate a 10% chance secondary effect on the ladder.
Trap Card: Activate an ability that requires foe contact on the ladder.
Your Time Is Up: KO a foe with Perish Song, Future Sight, or Doom Desire on the ladder.
Illegal!: Enter a current-gen ladder battle with a team not allowed in modern-generation Anything Goes. (think playing CAP, OMs, Pet Mods)
New Wave: Win a ladder match where you set Trick Room or Tailwind on the first turn.
Change of Scene: Win a ladder match where you use a move to set a weather or terrain on the first turn.
Love is in the Air: Win a ladder match where a foe is immobilized by love.
Sleep Tight: Win a ladder match where you successfully land Dream Eater or Nightmare.
Pointless: Win a ladder match after using Spite 5 times, using G-Max Depletion 3 times, or successfully using Grudge.
Not How I Thought You’d Do That: Win a ladder match after statusing a foe with Nuzzle, Poison Fang, Inferno, or Tri Attack.
Power Hour: Win a ladder match after KOing a foe with Stored Power or Power Trip.
151 Win Streak: Win a ladder match with only Generation 1 Pokemon.
Mustered Luster: Win a ladder match with only Generation 2 Pokemon.
Hidden Gems: Win a ladder match with only Generation 3 Pokemon.
Undistorted: Win a ladder match with only Generation 4 Pokemon.
A Balanced Team: Win a ladder match with only Generation 5 Pokemon.
Fay Reverie: Win a ladder match with only Generation 6 Pokemon.
The Beast that Summons the Victory: Win a ladder match with only Generation 7 Pokemon.
Dynamic, Gigantic, Eternal: Win a ladder match with only Generation 8 Pokemon.
Devout: Win a ladder match with only Legendary, Mythical, or Ultra Beast Pokemon.
Relic: Win a ladder match with only Fossil Pokemon.
Cross That Off: Win a ladder match with only Pokemon in cross-generation evolution families.
Head in the Clouds: Win a ladder match with only Flying-types and Levitate users.
Juggernaut: Win a ladder match without losing any Pokemon.
Wish This Was Chess: Win a ladder match without using moves that can miss or that have a partial chance for a secondary effect.
Didn’t Double Check: Win a ladder match with an incomplete team.
Prefer In-Game?: Win a ladder match without using status moves.
Koga: Win a ladder match without using physical or special moves.
One Gear: Win a ladder match with all Pokemon holding Choice items.
AI: Win a ladder match without switching.
Unarmed: Win a ladder match without items.
Purist: Win a Ubers, OU, UU, RU, NU, PU, or ZU ladder match with all Pokemon sharing a type.
Underrated: Win a Ubers, OU, UU, RU, NU, PU, or ZU ladder match with only Pokemon below that tier.
Sneaky Stone: Win a Ubers, OU, UU, RU, NU, PU, or ZU ladder match with all Pokemon weak to Stealth Rock.
In Development: Win a Ubers, OU, UU, RU, NU, PU, or ZU ladder match with only Pokemon that can evolve.
Motley Crew: Win a Ubers, OU, UU, RU, or NU match where all Pokemon are in different tiers. BL tiers and “ZU by technicality” form separate tiers.
All Skill: Win a Random Battle ladder match without losing any Pokemon.
Fate’s Hand: Win a Random Battle ladder match without switching.
Littler Cup: Win a Little Cup ladder match with all Pokemon Level 3 or lower.
A Little Bit Bold: Win a Little Cup ladder match without using Eviolite or Berry Juice.
Purist Among Purists: Win a Monotype ladder match without any secondary types.
Type: Null: Win a Monotype match without using any moves of your team’s type.
One… versus… one...: Win a 1v1 ladder match with only one Pokemon on your team.
Hope This Works: KO a foe in 1v1 with a recharge, two-turn, or crash damage move.
I Hate Species Clause: Win an Anything Goes ladder match with multiple team members all sharing the same species and forme.
Why Am I Here?: Win an Anything Goes ladder match with an OU-legal team.
Tourist: Win a CAP ladder match without any CAP Pokemon.
Local: Win a CAP ladder match with only CAP Pokemon.