The game starts out with the Robotech Expeditionary Force returning to Earth and fighting the Invid Forces. One of the ships crashes on Earth and the crew begins fighting the Invid close to one of their hives. One member of the crew (the main character) makes a mad dash on foot to assault the hive but is knocked out by an Invid Scout.
Four years pass and humanity is still fighting the Invid. The member that was knocked out wakes up with no memory in the rear of a truck being driven by soldiers, he then dons the name Locke by taking the armor of a fallen soldier that went by that name. Then meets up with squad leader, Silas and his partner, Arturo. With the squad low on ammo, Locke looks for Sam, a member that is guarding protoculture ammo reserves. After Locke needs his cyclone repaired he meets Guppy, who repairs his cyclone and tells him to meet him in a Town called Greystone. Soon after they find an abandoned ship and replenish their equipment. Finally (and after various skirmishes with the Invid & other hostile humans) they head on to Reflex Point, where the final attack on the Invid Invaders is set to take place at the end of the game.
The second Robotech game produced by Vicious Cycle, VC chose to focus on the next most popular section of Robotech, The New Generation, in part due to the choice of mecha available, the famous Cyclone. Instead of the distinctive, but by then overused, cell-shaded style of Battlecry, Invasion has a more normal 3D textured graphic look. As with Robotech: Battlecry, Invasion used a number of the original Robotech voice cast to reprise both their old roles for cameos as well voice many of the new characters introduced in the game.
Due to lower than expected sales of Robotech: Battlecry on the Nintendo GameCube, due in part to the delayed release of the GameCube version, VC chose to only develop the game for the PlayStation 2 and Xbox. It was also decided release a single version, instead of normal and bonus packed Collectors Edition sets like those seen with Robotech: Battlecry. Treated as a budget game, Invasion was deemed a fan-only title by many reviewers who favored other games in the same style released around the same time such as the extremely popular Halo 2. Ultimately sales of Invasion were much lower than Robotech: Battlecry.
The musical score of Invasion was composed by Jesper Kyd, a famed video-game music composer. While this was hyped up by Vicious Cycle and mentioned on the back cover of the game, Kyd's lack of exposure to Robotech meant his score had little links to the original TV score. For this reason many fans of the series consider it to inferior to Robotech: Battlecry's more mundane modern remixes of the TV series score. Like Battlecry, Invasion's soundtrack was released on audio CD, though available separately and not as part of a Collectors Edition.
Much like Robotech: Battlecry made an official design out of a slight variation in the VF-1R Veritech, Invasion made use of two formerly unofficial designs, the unrealized Devastator and the fan-created Shadow Dancer. Unlike the heavy licensor support the VF-1R received, these designs got little fanfare and slipped back into obscurity again.