The Gradius series, better known as Nemesis in the UK, first made its way onto our screens in 1985. Its horizontally-scrolling levels, multiple-weapon upgrades and massive end-of-level bosses set a standard for the genre. Gradius Collection for the PSP is a compilation of the first four arcade games - the original Gradius (aka Nemesis), Gradius II (aka Vulcan Venture), Gradius III, right through to 1998's Gradius IV. The collection also includes the previously unseen Gradius Gaiden. However, as the keen-eyed Gradius fanatics will note, this collection doesn't include the spin-offs from the Gradius stable that are Salamander (aka Lifeforce) and the cutesy Parodius.Each of the games included in this compilation offer players the kind of exciting shoot 'em up action one would come to expect from the Gradius franchise. As many fanatics of this genre will already know, these classic shooters are notoriously difficult. Movement is often tight, enemy fire can be at times overwhelming, and the end-of-level bosses are no stroll in the park. Gradius Collection for the PSP is no exception. There are countless enemy crafts baying for your blood and without the weapon upgrades, progress would be virtually impossible. In a fashion now staple to spacer shooter games, after destrying certain fleets of craft a golden icon is left which illuminates a weapon list at the bottom of the screen. Collecting successive golden icons will highlight more powerful weapons. These can be used to add secondary weapon units, such as missiles, lasers or force fields. Another feature that can be upgraded is the speed of your craft. In Gradius III and IV directional lasers and missile systems can also be added.Gradius Collection for the PSP includes media elements taken from all the Gradius games that make up this compilation. In the Gallery Mode gamers can listen to music from each title and watch trailers from some of the original releases. Players can also use the full PSP screen or change the orientation to view the game in its original arcade aspect ratio.