This would be an exellent idea for a game. I wold definitely give 10000/10 rating for that game.
Edit: Also maybe you can make the zombie population decrease gradually (killing) and/or make the human population slowly increase (repopulate)
Great game, I think this game will entertain people for a good amount of time, if not forever. 10/10 for a first level. Make more levels.
Edit: There are already some crazy machine level but those levels where made with phun, so I hope you use some of the algodoo features
What do you mean by "upload your own, better or nicer, solution.". Do you want us to just upload the solution or do you want us to make our own materials that will achieve the same objective in a different way?
What do you mean by 'not working'? Do balls not hit it, or do the spawned balls not touch anything? I set the collideset as 37 (A, C, and F). It seems to work perfectly for me. Maybe download it again.
Very good explaination but not that accurate. When you go some distance away and stop moving, there shoud be no visible shift because redshift is due to acceleration, not distance. There's other bugs, but it's still good though. 9/10