My game is going to be a role playing game with turn-based battles, much like the Final Fantasy series.
The sections I believe would most benefit from concept art would be:
Characters Design:
Main protagonists
Main antagonist
Key weapons
Main skills/spells
World/Level Design:
Key locations
Interface Design:
Game title and logo
For this entry, I chose to show the main protagonist of my game, Michio and an exotic in-game location, the city of Windgate
Michio
Michio, the former leader of the Imperial Assassins Corps.
Windgate
The legendary city of Windgate, the oldest and most technological advanced location in the game. It's the only location from the Old World that remained intact, because it is located in the sky.
