Tower/Castle Defence Game Maker

What all should I include in it? Right now I am in designing everything I need before writing code. I started with database design. 1 database per game and file management.

I got for my folders
files
files->images
files->images->defenses
files->images->enemies
files->images->intros
files->images->misc
files->sounds

for databae I got 4 tables which will be created.
waves: bg_music, wave_id, intro_pic
settings: intro_pic, num_waves, is_story_mode
enemies: e_type, e_health, e_speed, e_wave, e_name, e_sound
defenses: d_name, d_type, d_price, d_sell_price, d_dmg_ground, d_dmg_air, d_splash_dmg, d_dmg_air_distance, d_dmg_ground_distance, d_dmg_splash_radius, d_reload_speed, d_mini_icon

Then when people load up the maker, they can choose to load game in making or start new

If starting new, the'yll be asked if wanting story mode, and choose name of game, .ico for exe and splash screen image.

From there, they can create new waves choosing bg music and intro pic (if story mode is choosen)

They will also be able to create new enemies, ground enemies or air enemies with there health and animation frames.

Same goes for defense, they can set the properties for it and a 32x32 img for it in game when selecting the defense from menu.

anything I'm missing? or should that about cover it?