Sean O'Connor's Games

I have three questions relating to missiles:

1) Can I make a new one?

2) Can I make a near instant hit or beam weapon (a la Star Wars, Babylon 5, or Star Trek)

3) How are the missiles named

I think that red dots is not quite such a good idea: A fellow student in my mathematics class can't discern red and green.

I can find nowhere on Sean's page to indicate where I can download Rats!, nor any indication that the game is even still available. Am I wrong in assuming that the shareware versoin is a download?