Genre: Turn-based roguelike
Setting: Post Apocalyptic - Roman Empire inspired
Resolution: 640*480 + Full Screen support
Grid resolution: 16*16 or 24*24
Map style: Floor based, may contain a small world map screen
Lighting: Dynamic light sources and shadow casters.
Player races: Human
Classes: Your usual large class selection
Skills (which act as stats): Power, Dodge, Block, Hit, Critical,
Magic: Varying effectiveness depending on the Faith of target. Mainly
consists of debuffs and support spells.
Deities: Important only if you have high Faith. It will be hard to
keep good relations with Good Gods.
Randomness: There won't be many enemies who can instantly kill you.
I've also designed item statistics and bonuses, but I don't think they
will be of interest to you. For now, at least.