Have anybody noticed that right below "Treasure" when you open the game it says "Proyect RS-2"? I read about another shooter by Treasure for Sega Saturn called "Radiant Silvergun" which was considered the best shooter of all time for... um, some time. It seems you could only import it and that it contains a big gem like the Okinokai for last boss. It also say the message "No Refuge" when you are going to fight a boss. It seems Ikaruga is a sequel in spirit to this game, 'cause the story has nothing to do with Radiant Silvergun.

Yes, thats true, while they arent totally related, and you cant really call them 'sequels', they do share a lot of similarities. Ikaruga also owes a lot to another Treasure shooter called 'Silouette Mirage' (sp), that also features a type of attack called 'Layer attack'

Radiant Silvergun is a little over-rated though, good game, nice anime styling and the sword weapon is cool, but not worth some of the money people have been paying for it, i prefer Ikaruga, its a little more refined in its gameplay, its masterful in its simplicicity, whle RS is a little more... random.