Pokémon Go Fest will be remembered among 2017’s many disasters, but the mobile game’s developer is already taking more swings at the outdoor event space. This weekend’s Pikachu Outbreak, a special week of events in Yokohama, Japan, saw more than two million players successfully playing the game together outside.

The celebration included Pokémon Go Park, which encompassed various parks in Yokohama and gave players opportunities to catch rare Pokémon; and Pokémon Go Stadium, the week’s marquee surprise that ended with a legendary Raid Battle against Mewtwo.

Niantic said that the event went off without a hitch, which may have Pokémon Go Fest attendees scratching their heads. How did the developer manage to keep the servers stable for millions of people over seven days, when the game hardly worked for Pokémon Go Fest’s sub-20,000 attendees over the course of eight hours?

There’s myriad differences between Pokémon Go’s Japanese outdoor events and Pokémon Go Fest in Chicago, though. For one, that two million number applies to an entire week of players popping in and out of the various playgrounds. We asked Niantic for average concurrent player numbers, and will update when we hear back on those.

Players weren’t all concentrated in one area, either, unlike the Grant Park-based Pokémon Go Fest. That was intentional, a Niantic rep told Polygon.

“Niantic carefully distributed spawns of special Pokémon such as Unown, Shiny Pikachu, Chansey and Larvitar across the area so that Trainers were incentivized to capture and move through the greater festival area rather than staying in a single location,” the company said.

Niantic did more than that to ensure that Pokémon Go’s first live event since Pokémon Go Fest would succeed. The company had “all of the major Japanese [cell phone] carriers on notice,” it said, to make sure that data connections were in tact. That was a big issue in Chicago, where players struggled to get their phones to connect.

The big finale, a huge Raid Battle against Mewtwo, was also “tightly scripted,” Niantic said. The company worked to parcel out the servers so that they wouldn’t crash as catastrophically as they did in the U.S.

Pokémon Go Fest remains a dramatic dark stain on the mobile game’s track record, but the Japanese events suggest that Niantic’s learned some lessons from Chicago.