The object of this arcade-like game is to survive through a number of levels while crushing the "beasts" (represented by the character ├┤) with the movable blocks. The H's are attracted to the player's position (represented by a "diamond-like" character ◄►) every move. The beginning levels have only the common beasts ("├┤"), however from level H and forth the more challenging "super-beasts" appear. These are represented by "╟╢". These "super-beasts" are harder to kill as they must be crushed against a static block. At level P the eggs are introduced, implying greater challenge. These enemies are dormant at the beginning of each level, but will in time hatch into a "hatched beast" (╬╬). These beasts are the hardest to kill, as they can also move blocks to crush the player. They can however be killed as easily as the regular beasts, against any object.
Source: Wikipedia, "Beast (video game)", available under the CC-BY-SA License.