In the fourth stage of Story Mode, if you take the left path, there are a bunch of very slow-moving fishes that appear near the beginning of the stage, you must kill them all.
How many? I've been killing them all and still no achievement.
Edit: The achievement unlocked at the END of the level right before the boss...
«‘-•·÷·- ¥ámá -·÷·•-`»
Last edited by yamayamayaamaa; 12-13-2010 at 08:41 AM.