The phrase "Fire at will" said by the Redcoats gains a double meaning when referring to Terry, as both the redcoat and Terry are voiced by Will Friedle.
The monuments stolen by Chronos seen during the episode are: Jupiter of Smyrna, The Trojan Horse, Two Moai Statues, The Leaning Tower of Pisa, The Titanic, The Parthenon, and The Great Sphinx.
Thanks to the temporal interference, John Stewart is briefly replaced by another Green Lantern, Hal Jordan. In the DC Comics Universe, Hal Jordan is the second human Green Lantern, and the first who is a member of the Green Lantern Corps. This is his only appearance in the DC Animated Universe, although his name was seen on a fighter jet in In Brightest Day... (1999).
Chronos' henchmen (DeeDee, DeeDee, Bonk, Chucko, and Ghoul) originally appeared as a gang of Jokerz assembled by the Joker in Batman Beyond: Return of the Joker (2000), voiced by the same actors. In that film, they did not have the powers/enhancements shown here, which were given to them by Cronos.
First appearance of Terry McGinnis in the series; who never appears unmasked in this episode.