Great single player, horrible multiplayer.
You can loot dead bodies to gather ammo or credits, which you can use at save points to buy additional ammo, medpacks or upgrades. Sadly most of the enemies are very similar, both in looks and behaviour. The story mode is also very easy to finish, especially since you can save and reload every few rooms and know in advance when and where you will get ambushed. Ammo and medpacks are very common so the games is slightly challenging only on the hardest difficulty.
What I really didn't like was the 2 player coop part. There are only 3 available levels to play which are separated from the story missions. Because the camera is zoomed very closely both players have to be standing right next to each other all the time, and the cannot get separated and go each their own way. There is no pause game feature and there also is no voice chat support. With limited supplies, communication and increased number of enemies this makes for some really unfair and clunky gameplay.
Alien Breed is a nice atmospheric experience packed with action and diverse objectives. The game feels similar to Dead Space and "Aliens" and will throw a few surprises your way near the end. It's a nice game just don't buy it solely because it has multiplayer as it really isn't designed with that in mind but rather as an extra feature.