Too Close for Comfort
While using Bomb Custom style, bombed when a bullet was 1 pixel away. (Free Bombs not counted)
(ARRANGE B only)
Simply select bomb style and bomb () when a bullet is next to you. Choose a stage with lots of bullets such as stage 3, and when you see bullets about to hit you, bomb. If it was 1 pixel away, you'll unlock the achievement. This achievement is about trial and error. If you fail your first 2 bombs; then simply quit to menu and re-select the level.