The Official Wiki links to the game's Discord, which is the primary hub for providing feedback directly to the developer, Zak (POPO) , and his team.
If you are looking to "create" a new ability for your character rather than a game mechanic, you can unlock advanced features like: Search results for: fruit battlegrounds
A high-speed dash unlocked by reaching level 100 with a fruit, defeating the Marco boss three times, and finding a secret book near the Dressrosa bridge. The Official Wiki links to the game's Discord,
While there isn't a direct "create a feature" tool within the standard interface for players, the community and developers provide several ways to influence or interact with new content. Ways to "Create" or Propose Features defeating the Marco boss three times