Castlevania vets and noobs alike will find a lot to like about this anthology that mixes old and new.
All and all, the remixed Rondo is a beautiful game which sounds great to boot. You can choose between the more traditional Richter Belmont or the animal-throwing Maria Renard and take on successive levels until you finally duke it out with and kill Dracula. Although being level-based like earlier Castlevanias, it is not completely linear-fare: Hidden in various places in the levels are alternate paths that lead you to alternate levels. Amidst these levels are hidden objectives that need to be accomplished in order to reach the actual end of the game. It may take some searching to find all of the routes, but it is not impossible to find them without having to look things up; some I even found on accident. Be on the lookout for those secrets, though, because, perhaps unfortunately, the included Symphony of the Night and old-school Rondo of Blood games are required to be unlocked through items found in the remix. Those craving to dive straight into the classic Symphony of the Night will have to put their craving in check. Fortunately, a built-in stage select feature makes it a lot easier to go back to a particular stage to find any particular secret you missed... providing you know you missed it, of course.
As for Symphony, it's all here and more. The strangely translated dialogue that was in the original PSX version has been straightened out a bit, for better or for worse (as unintentionally hilarious as the original dialogue was, I kind of liked it), a few bugs were fixed, and a few new bits of content were thrown in, like playable Maria (formerly only in the Sega Saturn version with a move-set similar to Richter's). The only noticeable lapse here is that the voices and text don't sync up much of the time, but this lapse is forgivable and not detrimental to everything.
The original Rondo of Blood shows its age a bit. The graphics are dated, and the music isn't as catchy for the most part. Still, this is the old-school of old-school and plays noticeably different than its remixed counterpart, enough to make it fun by itself.
Now for the most disputed issue of the game: the Difficulty. Symphony of the Night is pretty much on level for fans old and new, and ramps appropriately. The Rondo of Blood remix can reportedly be punishing for those who are not used to the vices of Castlevania, the original Rondo even more punishing. However, if you've been onboard Castlevania since the beginning, you'll probably feel well at home here, with very few parts of the game all that frustrating. It is certainly a challenging play, to be sure, but the challenges never feel all that cheap, and there are both continues and save points to help things along. As an old-schooler, I certainly had my share of continues (it helpfully keeps track of how much you suck... er... how much you continued... mine currently reads 27 thanks to a certain hidden special stage), but I never found any particular part of the game cheap or frustrating.
In short: This game is a great addition to any PSP game library. Old fans will appreciate the opportunity to play a game they weren't given a chance to, and new fans can experience everything Castlevania has to offer. 'Course, if you HATED the old Castlevanias, this pack probably won't change your mind, but for those looking for a definitive Castlevania experience, this is it.