Isn't worstfish on lichess?
Worst possible chess game

Yeah, it's even in Bullet Arenas now, I would love to list the usernames of some "players" who I know were really unfair sports in the Bullet Arenas, but then that would be against the "naming and shaming" rule here. Lol.
I recommended [another site -- VP] for features instead of getting a diamond membership and chess.com censored that name. They're probably going to censor it right now, but hint: that website starts with a l
Bro what?

The award for the Worst Tournament Player (before the age of computers) must go to Colonel Charles Paul Narcisse Moreau, who competed in the 14-player Monte Carlo 1903 tournament alongside such Masters as Tarrasch, Pillsbury, Maroczy, Schlechter, Teichmann...
... and lost all 26 games. Final score for the tournament: 0-0-26.

There’s a difference

Is it really the worst possible game though? It's very easy to lose to "WorstFish", which means there are worse strategies than WorstFish.
Stockfish evaluation assumes you want to win, but just flipping that the evaluation doesn't take into account that if you want to lose, the best strategy given high enough skill is actually to dominate your opponent leaving just a pawn left, and forcing the loss. This avoids the risk of your opponent stalemating you by accident, as probably would happen to WorstFish, and I imagine that engines with this strategy would lose to humans 100% of the time (if resignations are flipped too)

Is it really the worst possible game though? It's very easy to lose to "WorstFish", which means there are worse strategies than WorstFish.
Stockfish evaluation assumes you want to win, but just flipping that the evaluation doesn't take into account that if you want to lose, the best strategy given high enough skill is actually to dominate your opponent leaving just a pawn left, and forcing the loss. This avoids the risk of your opponent stalemating you by accident, as probably would happen to WorstFish, and I imagine that engines with this strategy would lose to humans 100% of the time (if resignations are flipped too)
You are correct,its easy to lose, but Worstfish played all the worst moves, and the move that made it win is the only move. So technically, since you made a mate in 1 for you a mate in 1 for him. You played better than it. So what you have to do for SF , its lengthy, but play moves continously until you see the lowest eval, it would take hours and maybe days. I am working on it rn
Put the game example in post #3 into game analysis - haven't seen so much red since donating blood at the local blood bank!!!
Look at arsenal fc