Yes, that is indeed Pac Man on his belt. Tales of the Abyss marks ten years of the Tales series for Namco, so I suppose that gave them the right to stuff as many shameless references into the game as possible. Other references include Anise's dolls and the ultimate haven for shameless Namco worship: Nam Cobanda Isle. Aside from the Colonel's interesting belt buckle, another odd thing about his appearance would be his eyes. Which are red. No, he's not a vampire, despite his joking to Anise that he drinks people's blood. While it's not explicitly stated in the game, the reason behind the odd color might be the fonic arte that Jade has applied to his eyes. Eyes are powerful fon slots, and Fonic Sight amplifies a fonist's abilities. However, only a powerful fonist can handle it, as evidenced in a side quest when Jade's self-appointed apprentice ends up blinding himself. Now, I'm not sure how one goes about applying fonic artes to their eyes, but apparently it's possible. Though Jade does mention that Mohs' power came from inscriptions. Also, Jade's Fonic Sight is the reason he wears glasses; his glasses are fonon-regulating in order to keep the fonic arte applied to his eyes from going out of control.

Additionally, Jade's character design went through some changes before the final version. Kosuke Fujishima's sketches reveal that Jade almost had short hair and a different uniform. And no Pac Man! Jade somehow manages to look more feminine with short hair. I don't get it. Or maybe it's the tiny waist? Hmm...