Looks like the original website for this game www.alienbreed.co.uk is down. I added a link to Flashjesterpunk's forum which is still up. Download is available in the first post.
Merely 18 years after Alien Breed was released on the Commodore Amiga, the developers "Team17" churned out a sequel in December 2009: "Alien Breed: Evolution". It appeared on Xbox Live Arcade and received generally positive reviews, despite repetitive gameplay and some multiplayer problems.
The first installment of the now "heavily updated" PC version will come out 3rd June 2010. Renamed to "Alien Breed: Impact" it will appear in 3 episodes via Valve's Steam service. At the moment a free demo is up.
Great remake by Flashjesterpunk of the perfect Amiga top down shooter by Team17. Still scary and frantic action galore, with extremely nice touches. Welcome to Intex Systems.