Boobeam Trap

Buebeam Trap (ブービームトラップ) is the boss of the fourth Wily stage from Mega Man 2, a resistant protection system. The room has five flashing beam guns in the walls that fire simultaneously at intervals, indicating they will fire when they flash faster. They can only be destroyed with the Crash Bomber. The room also has some Destructible Blocks protecting beam guns.

Strategy
The boss requires strategy to be defeated, as the player can only use seven Crash Bombs, five being to the guns and two of the breakable blocks that are in front of two guns. The other blocks don't need to be destroyed, being possible to pass by them with Item-1 and accurate jumps. If the player run out of Crash Bombs, he will be unable to defeat the boss until he is defeated, returning to the checkpoint before the first moving platform and being able to refill the weapon's energy before returning to the boss.

If the player is willing to intentionally die at the boss, it's also possible to defeat it using only five Crash Bombs in their second visit. To do this, the player must arrive at the boss room and destroy several blocks, two being at least the left-most wall and bottom-right wall, then get defeated. After which, they would refill their weapon energy on the enemies between the checkpoint and the boss room. Upon entering the boss room again, any walls they destroyed their first time around will still be gone. Note that the walls return if it was the player's last life.