That's because you, the user, are supposed to provide the graphics yourself. F0 is a programmer, not an artist. If his demo had plant stage graphics, he got them from somewhere else. This script is not designed to do everything for you. It's a tool that you have to work with.
Also, since this script was designed based on another game's system, the idea of 100 different seeds was never really a thought. Maybe the system you want cannot, and will not, be truly satisfied by this script.
And don't double post within 24 hours.