The confusion stems from early internet mislabeling. True Pokémon Diamond & Pearl use dual screens, 3D-ish graphics, and touch controls — impossible on a Game Boy Advance. What does exist:
: A popular project that recreates the Sinnoh region, featuring a remixed DP soundtrack in GBA soundfont, replaced trainer and Pokémon sprites, and the Physical/Special move split. Pokemon Diamond And Pearl Gba Download For Android