Creating zombie game showcasing players' programming skill- Looking for advice

The basic idea of the game is that the people playing the game write a program or develop complicated (or I guess simple) instructions that zombies will follow. You will write the instructions and then upload the code to a website/server which is constantly running the game. The game will involve zombie “breeds” created by different players. Many different statistics would be available to players such as what percentage of the total zombie population is comprised of zombies that have their code running them. Of course the zombies would be trying to bite/infect humans :persecutioncomplex:. Uninfected humans would be injected into the world as needed by the game. I am thinking that at regular intervals the town is nuked, killing all zombies/humans, and perhaps at that point a winner could be declared based on some points system.

I want to provide a viewer program that gets data from the server and shows players what is happening much better.

I have a ton of ideas I am really excited about, but I am very worried about the process of creating a language people can use to program the zombies. I am not sure what considerations need to be made or really where to even start. I looked at what it takes to make a custom interpreted programming language, but I am not sure that is what I actually want. I will gladly describe anything about this game concept in more detail upon request.

Looking for advice specifically on the programming bit, but will happily take ideas and suggestions!