Aim your gun at a target and fire off at the appropriate time a couple of pretty explosive grenades. Focus your attention on all the scary creatures that lurk in barricades to hide nicely from any danger. Get them into your sights and shoot them all on a single attempt. If you succeed, you get a chance for achievement. Levels are not time-limited, which gives you enough space to think about the right way to do it. Do you after all fall to destroy all the monsters and in addition to that, they still gleefully grin at you? Simply restart the level and start with a clean shield. The humorous tunes are the right way to keep a good mood. On the other hand, the game is in some aspects a bit bloody, which may not be to everyone's taste.