Fort Walker appears in an open 27x27 square arena. It remains in the middle of the arena at all times. Its four legs constantly step back and forth in place. When attacking, or in order to be more evasive, it can slowly rotate its body to any degree by stepping around. Its central body, feet, and head can all defeat player characters on collision, and can eliminate bombs from the field without detonation. No part of the boss' body can reach the strip of squares bordering the outer edges of the map.
Fort Walker has two attacks, which are issued at random.
The boss raises its head, emitting flares, then lowers its head to one side. It emits a long breath of fire while slowly sweeping its head to the other side along the ground. The fire can detonate bombs.
Electricity generates around the top of the boss, and the central tower fires off. A fireball falls from the sky directly over the player character. When it lands, it erupts in a 6x6 unit circle. The explosion can detonate bombs.
The number of fireballs per attack depends both on difficulty setting and whether the boss is enraged:
- Beginner: 1 fireball.
- Veteran: 1 fireball, 2 when enraged.
- Expert: 4 fireballs, 5 when enraged.
On expert mode, when Fort Walker is enraged, it is capable of triggering the fireball attack in rapid succession with no pauses in between attacks, resulting in a steady stream of fireballs raining over the player.
Fort Walker's weak points are its four feet. When a foot has sustained full damage, its lights turn off. When all four feet have been damaged, the boss collapses, and the head lands on the ground. The head is the true vulnerable point.
After taking four hits of real damage (5 on Expert difficulty), Fort Walker will enter an enraged state, increasing its speed and rate of attack.
- The boss' original Japanese name, "Seventh Rank", is a reference to chess strategy. A rook on the seventh rank of the board traps the enemy king while affording a strong offensive position. This refers to the boss' fort-like appearance, which resembles a rook.
- The boss' localized English name, "Fort Walker", refers to one or two identically-named forts from the U.S. Civil War.
- Golem Bomber's original boss form from Super Bomberman 2, Fire Breast, also attacked by shooting fireballs that rained down from above.
- A note in the concept art indicates that birds were originally meant to fly around the top of the boss.