Of course to get any points you have to shoot the chickens, you will hit them better just with practice.

Unlike other crazy chicken games, you get no penalty for reloading early, so reload often. VERY OFTEN. Better reload far too often than not having bullets left to shoot.

The chicken at the pond will eventually give 50 points when it fishes the plug out of the pond and gets crushed by a safe. WTF is happening? I don't know either

This is the first thing i do in any round, I shoot the carparts: the bumper, the hood and the door.
Doing this will not only give you points but also enable you to shoot the chicken in the car, which you can easily shoot whenever you hear the horn. The chicken has like NO FEAR, you can aim at it for far longer than other chickens that hide.

You can kill the chicken that defends itself with a pan by alternating between shooting it in the head and in the belly.

Get the snail to the apple by shooting behind it several times. Be careful not to kill it.

What limits you from getting infinite points in crazy chicken? That's right: the timer, luckily there is a way to increase the timer: SHOOTING CHICKENS
There are 2 chickens that give you extra time when you shoot them: the flower chicken(left) and the chicken in the field(right).

Both of them are fairly hard to shoot, since they will only appear for a short time. I think they are both also very scared of bullets, so don't miss your first shot.


THEY ARE ABSO- MOTHERFRICKING -LUTELY YOUR HIGHEST PRIORITY TARGETS!
It's best to keep your view around where these chickens appear so you don't miss them.

The chicken on kites are worth more if you shoot the kite first. simple as that

You can try to win at blackjack by shooting the card, when the all the cards add up to 21 you get +500 points (and maybe some extra chickens to shoot at)

Sometimes in certain events (maybe if you win at blackjack) a huge flock of chicken will appear, far too many to shoot them one by one. For that reason you should ready up the machinegun at the start of the round when you don't have to shoot anything. To do that just shoot the tree a bunch of times (like 10+ times) until a key appears, shoot the key to get it.
When you need to use the machinegun just shoot keyhole of the X-crate. (the crate with the X)

You can get to the second level by shooting the sign to the right of the tree in the last 10 seconds after getting 900+ points. But don't go thinking that it will give you many more points, there aren't that many chickens in the second level and you have (as far as i know) no way of extending the timer in it. You should try to get as many points as possible in the first level.

First off: I don't know everything, I just wrote this guide because no one else has.
If you find something that should be mentioned, write a comment and maybe I will add that information and credit you here.