My Classmates Left Me Behind in Another World, and Now I Have to Survive the Colosseum with the Worst Ability of All

The Colosseum is an isekai-inspired sandbox game with transformation and combat mechanics. You arrive in a fantasy world and build power and influence by growing stronger through combat and recruiting members into your personal harem. The game emphasizes player agency and adult relationships—a departure from typical isekai tropes where the protagonist remains passive. Core gameplay involves stat progression, character transformation (with multiple form options for recruits), and harem building as you explore and interact with the world.