Glass

It us light blue in color and always called the glass block.Among the three kinds of blocks, ice is the weakest one.It can be beak by all kind of birds.However, levels with this kind of blocks are usually provided with some blue birds as they are very good at breaking ice.It is suggested to sprite the blue bird right before the bird crash on the ice block to maintain the greatest strength of the bird.Yellow should be avoided to crash on it as the bird will slow down and loss it's function.