I just picked this up last night. Got the only copy in town, out of four stores. I must say, this is one hell of a deal for $20. Three Raiden Fighters games, TONS of tweaks and options to customise the experience, and supposedly, some unlockable 'perfect game' videos.
On top of that, the games play beautifully. Raiden is one of the last holdouts of the type of shooter we all know and love on the PC Engine: the kind where blowing stuff up is the main point, not pulling of tricks like in Ikaruga or whatever. I dislike the newer style trick/score shooters that are more about chaining combos and gimmicks. I want lazers, bombs, explosions, and giant bosses, and lots of them!
This fits the bill nicely, and underneath the hood is a very clever (and unobtrusive) scoring system that adds quite a bit of depth if you are going for a high score.
Great value, and I think this one might end up being rather uncommon. Pick it up if you can. This is the best stateside shooter release since Gradius V and R-Type Final.