Also known as: ギャラクシーフォース
The third Transformers series in the Unicron Trilogy. It was preceded by Transformers: Energon. Due to the poor reception of it's predecessor, the show was originally made as a reboot in Japan, although the English dub added in cameos from the previous series' casts to continue with the original plan of the series being a continuation. It was later retconned into the Japanese version of the continuity in supplementary materials.
The Japanese title is Transformers Galaxy Force.