As I said earlier,
Flock presents a beautifully simple idea that almost single-handedly sells itself. You control a space ship that needs to abduct animals for your mother ship, affectionately called the "Mother Flocker" (which makes you a "Flocker" I guess.) You control your ship around each level using your tractor beam to frighten animals and making them run into your Mother Flocker to be abducted.
It can't be fun if there isn't some sort of challenge. Each animal has a different behavior that it will use when running away from you and the trick is to herd them all together to make it easier to manage. There are plenty of animals to herd too. Chickens, cows, sheep and pigs are what you will see most and sometimes you have to use them all together to help them through obstacles.
At its heart, Flock is a puzzle game where the environments are the puzzle and the Mother Flocker is the ultimate solution. Using all of the animals is fun when it works well, but more often than not, you will be struggling to control them. Cows charge in the direction that you move them and they are the old standby to clear a path for smaller creatures. Chickens like to group together and can fly short distances if they fall from a high distance. The most frustrating creatures in the entire game, however, are the sheep. Not only is it incredibly difficult to herd them in the direction you want, but once they are in a herd, it is easy for them to break up and scatter across the map. If it weren't for specific goals and quotas to meet, I would kill every sheep in each level just so I could have fun.
The variety in the actual level design is creative and brilliant. Each new level adds another layer of complexity to the puzzles and I never found myself getting bored. As soon as you understand the behaviors of each animal, a new puzzle involving crop circles diverts your attention to help give you extra time to finish the level.
Although, if you ever find yourself getting tired of the single player, the robust level editor will offer a good way to unleash your creative side, but you have to unlock new parts to use by earning them in the single player. Another thing that is a problem with the level editor is the fixed camera angle. You cannot look around your creation because it forces a ¾ isometric view on the field.
There is a multiplayer mode as well, but it seems like a waste since it is local multiplayer only. Online multiplayer seems like a smart choice for a game like Flock, so it seems odd that it is absent. You will need two controllers and a friend to sit on your couch and an entirely separate campaign opens up with new unlockables that can only be earned here.