A great thanks to all ndless/nSDL developers! I got this in less than 5 hours thanks to these libraries available.
I deleted all the musics or voices (as there is no way to play them back). Now the main program is 384KB in size while the resources are 21.9MB total. Monochrome models will run the game, but that would take up all the available space. I am thinking about further compress it. Save/Load not working currently.