Okay so if the crew got the box during true colors and then ran away to Earth, as was the plan, I think things would've been a lot worse off. My reasoning is that since the box powered the rockets that kept the castle afloat, its absence would've caused the castle to fall. That's great since it would likely have killed The Core and Andrias, but it would've also killed General Yunnan and Lady Olivia, not to mention Grime and Sasha if they had stayed, as is likely. Then, if you take into consideration that the castle was still above Newtopia, and the citizens didn't have nearly enough time to evacuate, this would've skyrocketed casualties exponentially. This also likely would've cause severe flooding and mini tsunamis, seeing as a large amount of seismic force(earthquakes) would've been released as a result of the impact. Looking at the Amphibian map, you'll see that the placement of the impact point(Newtopia) would lead to the destruction of several small towns along the coastline, as well as nearby towns inland.