Alien Breed: Tower Assault takes place on a distant planet where a scientific outpost has been attacked by an unknown enemy. A team of marines is sent to investigate and destroy the attackers. As their dropships approach the base, they are met with wild bursts of laser fire from damaged defense lasers.
The gameplay follows your soldier as he navigates through levels, collecting keys, ammunition, and credits while fighting off the alien force. The game offers a non-linear experience, with most levels having multiple exits, allowing players to approach the game in different ways. The levels range from indoor to outdoor environments, with a focus on multi-level towers where you'll spend most of your time.