Many already know this but if you don't have Wardcliff Coil yet then you probably don't. The little rockets will catapult certain enemies far away. When a chest spawning target (I don't know what it's called in the English version) is near the edge of one of Titan's platforms, don't face the water when you're shooting it, or you will send your target flying into the water and the chest will be spawning in or above the water (and therefore be unaccessible). It's hilarious but impractible. Make sure that the target is far away from the platform edge or that you're not facing the water.