In all the talk of graphical downgrades no one seems much preoccupied with 'why?'. Why build something and then proceed to tear it down, piece by piece, in the hope that ever more diminished expectations about the final product won't be severe enough to...
On the iPad version, you don't actually have to pull back as far as you think (otherwise your thumb goes off the edge).
Use the catapult unless you're a masochist.
Upgrade your reload time unless you're a masochist.