[2] In these games and their sequels, the player assumes the role of a Trainer whose goal is to capture and use the creatures' special abilities to combat other Pokémon.

When developing the games, director Shigeru Ohmori wanted to put the spotlight on the Pokémon themselves, re-examining the concept of them as living creatures and how humans interact with them.

In an interview, he described "nature" and "abundant life" as two of the central themes of the game, while also wanting to explore concepts of "Pokémon that have a more playful element or a gimmick".

[5] As the games also represented the 20th anniversary of the franchise, the development team were encouraged to explore a "funny element" to Pokémon design, as it was seen as a special occasion.

Consideration however was also given to "find a balance of cool [and] serious" Pokémon designs that would fit the game's Alolan region,[6] which was based on Hawaii.

[25] In a Twitter poll held by The Pokémon Company International, Popplio was the least popular of the three starters, receiving only 21 percent of the vote.

[26][23] According to Kotaku's Patricia Hernandez, Popplio "attract[ed] indifference, hate, or worse, straight-up pity.

Multiple writers decried Popplio's design as the worst of the starters, with negative comparisons being made to prior first partner Pokémon Piplup.

[30] Other reasons were highlighted by Paste writer Janine Hawkins, who stated that Popplio's confidence led to it being considered a Pokémon that was fine on its own, and in conjunction with its design, did not have design quirks that led to being well-liked in comparison to other Pokémon introduced in Sun and Moon, such as Rowlet and Mimikyu.

[31] In response to the criticisms, Pokémon Sun and Moon director Shigeru Ohmori stated that "I personally think that Popplio was very cute and he'll be very popular with a lot of people.

[11][24] Brionne received mixed responses initially, with The Verge's Megan Farokhmanesh noting that it seemed awkward in terms of design.

Similarly to Popplio, many rushed to defend Brionne's design, with supporters of the Pokémon growing at a large rate.

[37][36][11] Polygon writer Allegra Frank noted that Popplio symbolized how many "were downright hard to look at in our youth" citing that its evolution into Brionne showed the Pokémon becoming more confident.