Rise of the Roach
The main plot enjoyment of this episode came from the Raph/Spy Roach storyline.
The plot is that Donatello puts spy equipment on a cockroach in order to spy on the Kraang who are planning to use a laser drill to tunnel to the center of the planet and flood New York with magma. However, the Spy Roach gets mutated into a bionic monster seeking revenge on the roachaphobic Raphael for his attempted assault on the insect.
As I said, Raphael having to continually face his fear as the mutated Roach Terminator attempts to reap vengeance upon him. His fears causes him to cause the team to fail in their attempt to stop the Kraang. This caused Leonardo chastise Raph but his fears seem perfectly valid to me. I know the turtles fight mutants on a regular basis, but seeing your fears get turned into a monster that wants to kill you and then see that monster grow into a even bigger and more horrifying monster is a perfect excuse to be frightened. However, the story is handled pretty well in my opinion with many funny jokes and terminator references.
The second plot is that the Kraang is stealing a diamond to use as a lens for a laser drill in order to borrow to the center of the Earth and flood New York in magma in order to begin "phase two" of their master plan. I haven't the slightest idea how this fits into their terraforming plan or the plot to kidnap April. In fact, it seems counter productive because they're destroying the planet they're trying to conquer and potentially killing the girl they're trying to capture. Also when Raphael uses the the laser drill the vanquish the Roach Terminator he doesn't destroy it. What's stopping the Kraang from simply rebuilding it and what about the hole they drilled into the Earth? I think a hole only 100 meters from the Earth's core will cause some problem. I dunno, hopefully this will get explained in later episodes.
8.5 out of 10