Textures (heightmap, feature map, historical map for main menu)
Description / general data about battle (location, year, parties, transcribed description)
Encoded battle data (Positions of units and course of battle - only used for genetic algorithm)
Situation data (Positions of units and their stats - used for simulation, default situation is generated by genetic algorithm) plus a preview image per situation
must-have: position of units could-have: per-battle balancing data