Pokemon Dark Worship is a ROM hack for the Game Boy Advance, likely built upon Pokemon FireRed or LeafGreen. It is a fan-made project independent of Nintendo and Game Freak. The 'Dark Worship' in the title suggests a darker theme or storyline than the original games. Gameplay would be familiar to Pokemon players, but the storyline and characters should be significantly different. Specific details about development history are scarce but the title hints at a darker and more sinister plot.

Pokemon Dark Worship

Pokemon Clover v1.3