Set-up a 2 player multiplayer game with the following settings:
Rules: Battle Royale
Player: 4P
COM Level: Off
Sets: 1
Time: 9
Start Position: Fixed
Revenge Carts: On
Pressure Blocks: On
Skulls: On
Special Abilities: On
Pick 'Pitfall Zone' & any Bomber Types for controllers 1 and 2 then select 'None' for the other two player slots.
When the game starts, begin dropping bombs next to all the blocks in the arena, picking up all the power items that spawn as you go along. Once all the blocks are destroyed drop a bomb on yourself to unlock this achievement.
If you followed the guide, after picking up 7 Bomb items you will also unlock: