Gradius Collection, known in Japan as Gradius Portable(グラディウス ポータブル,Guradiusu Pōtaburu?), is a compilation of five Gradius games, converted for play on the Sony PlayStation Portable by Konami. The games were reprogrammed to take advantage of the PSP's wider display, as well as allowing players to play each game in their original aspect. Four of the games were taken directly from the arcade game, while Gradius Gaiden was a Japanese only release for the PlayStation. It is a compilation of the following games:
The original game and "II" are based on their updated versions included in the compilation Gradius Deluxe Pack for PlayStation and Sega Saturn, while "III" and "IV" are based on theirs included in Gradius III & IV for PlayStation 2. In fact, in the game here is the possibility to view the starting intros of these two compilations, in addiction of that of Gradius Gaiden.