Graphics? Check. And simple, top down, tilesheet or character maps work just fine.
Battles? Check. You can leverage anything from purely functional, object oriented, websocket, long polling, SQL, you name it. Whether you use 3 elemental types or flesh out everything from multiturn, semivulnerable, exp/leveling, it's all up to you.
Wanna just build an REST/GraphQL/gRPC API? Or a UI? PokeAPI is an opensource database of nearly all game data from moves, items, and species.
Pokemon is an endless, any-scope, extremely documented, opensource-rich field of exploration.