The objective is to destroy all balloons. Each stage features a randomly-generated map gridded with hard blocks (that cannot be destroyed) and soft blocks (that can be removed with a bomb, and may contact a special item).
The balloons will change their expression and colour randomly. This appears to determine how they will behave, from indifferent to vicious in their pursuit of Bomber Man. Colliding with a balloon or getting caught in a bomb explosion will kill Bomber Man, and will generate a new stage.
All levels are randomly generated including Bomber Man's starting position, block placement and enemy placement. This can be unfortunate instances of the enemy spawning too close for the player to react.
Bombs are laid with the Space Key. An infinite number of bombs can be laid, and all bombs have a 2-tile blast radius. Unlike later games, bombs can be set 'off-centre' (as in, not aligned to the centre of a tile on the grid - if that helps confuse you more); the resulting bomb blast will be 'halved' (see screenshot), but will still damage enemies and soft blocks.
Likewise, soft blocks can be 'half-damaged' if only the very edge of an off-centre bomb blast touches it, leaving half the soft block standing.
Bomber Man and balloons can walk through bombs. You can't use bombs to trap enemies in corners.
Hidden in soft blocks are two kinds of special item. Exit Portals will immediately move you to the next stage, regardless of how many balloons are left. Bonus Points (depicted as treasure chests) will award you with roughly 1000 points to your score.