Bomba updates the game with current rosters, Brazilian translations, a custom theme song, and even meme teams (like a team of real players that all went to prison at some point, and the whole team is in matching prison gear. They’re still updating to this day! The Patch was originally sold on discs, but has since moved to online distribution.
They were much more tactical and had better controls too, visually and audio better and just more polished. The PES series (before they renamed it from ISS) were just the better games back then. I started with International Superstar Soccer Deluxe on the SNES and wasn’t even a big sports fan. But got obsessed (well not that extreme maybe) with this game. And then the Nintendo 64 followup International Superstar Soccer 64 was phenomenal! Everyone compared it to FIFA 64 and it was clear and cut which game was better for the majority. I’ve played PES98 on original PSX too.
Today, people can’t understand how good these games were back then compared to any other football/soccer game at that time.