PSP Vault reports that the Official Gradius Portable website has posted some wallpapers to celebrate the release of the game (titled Gradius Collection in North America).

The game is available to import for us non-Japanese over at Lik-Sang with the US release sometime in Q2 of this year.

The Gradius Collection contains radius I, II, III, IV and Gradius Gaiden all on one disc. For those who have never played the Gradius games, be prepared for some of the most difficult side-scrolling games known to man.