Speaking of special abilities, Rogue Galaxy has one of the weirdest leveling systems we've seen outside of Final Fantasy. You'll power up the normal way - by defeating enemies - but to unlock each character's special attacks, you'll need to tackle their "Revelation Flow." This is basically a big flowchart, with slots for rare, seemingly random items like twigs, hunks of ore and fruit; fill up all the slots in a skill box, and you'll earn a new ability and open up paths to even more hidden skills.
You'll also open up questions, such as "what are the characters supposed to be doing with this stuff? Are they eating the fire extinguishers and slabs of metal? Taking martial-arts lessons from them? What?"