Players can select to play the game in Arcade and Saturn modes, representing the two platforms the original first appeared on. All the gameplay systems are in tact, of course, as is the background music from Hitoshi Sakimoto.
New features for the XLA version include:
Two player cooperative play via Xbox Live.
Online score rankings.
Upload and download player data. This will let you watch high quality play from around the world.
Greatly improved visuals. You can also play using the original graphics, though.
As a hidden bonus, an Ikaruga shooting style mode.
Wicked! Radiant Silvergun is one of the more rare Sega Saturn titles, and is highly sought after by collectors. It's one of the more hard core shoot-em-up titles I've ever played (same goes for the semi-sequel, Ikaruga) - so be ready for a challenge.