And when you begin to grow tired of all this agreeable but repetitive nonsense - not to mention punful dialogue like "Oh my gooness!" and "I'm blubbocating!" - you'll discover that you haven't just been collecting random items over the course of your questing. You've been collecting ammo.
For your giant tank. To use on other giant tanks.
Rocket Slime's craziest idea happens to be its juiciest feature as well, and the reason you'll stick around after the rest of the gameplay grows tiresome. Commandeering a multi-storied war machine with the equivalent of a smiling Jello shot requires a surprising amount of strategy. There are large assortments of weapons, each with distinct damage effects, and a diverse group of slimes from which to build a crew. Don't like your basic options? You can always create new weapons by combining items with alchemy, or add new squad members by recruiting from the monster population you encounter.
Unlike the rest of the game, the tank mode also takes advantage of the DS's unique capabilities. Though the stylus is never put into play (why it's not used to sling Rocket around maps is beyond us), the dual screens are essential for keeping tabs on your enemy's attacks and planning the proper counter-fire. Plus, with wireless multi-card options, that enemy can be your real-life friend instead of another random woodland creature.