Pokémon Pokopia's first paid expansion, Bubbly Basin, responds to a significant gap in the base game's creature representation by introducing underwater mechanics. The DLC transports players beneath the surface to restore a sunken settlement where aquatic Pokémon species—previously relegated to minor roles—become central to gameplay. This environment-specific design enables water-type creatures to display their characteristics in settings deliberately built to highlight their unique qualities.

The timing of this underwater-focused content proves relevant given the direction of recent Pokémon releases. Contemporary mainline entries have progressively reduced underwater exploration and aquatic creature prominence in favour of land-based open-world environments. Bubbly Basin reverses this trend by dedicating an entire biome to species that typically receive minimal spotlight, illustrating how environmental context can substantially alter player perception of character designs that might otherwise seem overlooked.