Ikaruga was the first Treasure game to have an official Superplay produced for it.
The GameCube version of Ikaruga is the only version that does not have intro text for each chapter.
Two of Ikaruga's gameplay's main mechanics hail from Treasure's earlier games. Ikaruga's chaining system is a modified version of the chaining system used in Radiant Silvergun, while its polarity mechanic was first utilized in the Treasure platformer Silhouette Mirage.
Ikaruga's in-house development team consisted of 5 people:
Hiroshi Iuchi — the director of Radiant Silvergun, who was Ikaruga's lead game designer, background designer, and music composer.
Atsutomo Nakagawa — who was Ikaruga's main programmer.
Yasushi Suzuki — the lead artist from the original Sin and Punishment, was also Ikaruga's illustrator and character designer.
Satoshi Murata — who created Ikaruga's sound effects and edited the game's background music data.
Masato Maegawa — Treasure's founder and CEO, who was Ikaruga's executive producer.
Ascended Fanon: There are some known score runs of the game where people would play the two player option on their own controlling both ships at once. The PC version now has that as a built in feature allowing players to play single player with both ships at the same time with just one controller.