Alundra 2 has, it can be debated, a bad reputation. I say it can be debated because it's generally more accurate to say that Alundra 2 has NO reputation, being a very obscure old RPG from the Playstation 1 days that got even less attention than its already oft-forgotten/ignored predecessor, Alundra 1, did. Generally speaking, no one but the big RPG enthusiast is going to even know what Alundra 2 is, should you ask.
The obscure-RPG-playing community, however, does have a general opinion of the game, from what I've seen, and that opinion is that it's just plain bad. Where Alundra 1 is generally praised in the gaming circles where its existence is known of, Alundra 2 receives, in those same circles, scorn and avoidance.
I think the main reason that people hold such disfavor for it is that it has nearly no ties, technical or thematic, to Alundra 1. It's not surprising that gamers would hold that against Alundra 2; after all, most of the people who would be interested in seeking out and playing Alundra 2 do so, I imagine, because they're fans of Alundra 1 and want more of the same. But Alundra 2 is just nothing like Alundra 1--no common characters or plot (there's no reason to think it even takes place on the same world), the gameplay style is notably different, as is the atmosphere and general look. About the only real connection they have is the title of the games and the fact that some of Alundra 2's music sounds like some of Alundra 1's. Alundra 1 is moody, Alundra 2 is lighthearted. Alundra 1 brings about surprising emotion, Alundra 2 goes for chuckles. Alundra 1 has subtle themes and a conflict between gods and men, Alundra 2 has a straightforward save the world adventure. Alundra 1 has frustratingly difficult puzzles, Alundra 2 has frustratingly difficult controls. Alundra 1 looks okay, Alundra 2 looks like something that was dug out of the garbage bins at Naughty Dog, Inc. while it was developing the first Crash Bandicoot. And so on.
Thing of it is...well, it's not warranted, this general dislike. Alundra 2 isn't a bad RPG. Oh, it's not an especially good one, either, I'll certainly grant you, and between the 2, Alundra 1 is clearly the superior RPG. Better ideas, better characters, better story, better execution overall. But Alundra 2 is, if not outright good, certainly a decent RPG, and enjoyable enough from start to finish that you shouldn't feel your time spent with it wasted.
What you have to realize, I think, is that this game, despite obviously trying to cash in on the meager fame of Alundra 1, knows what it is and does not try to be more. What it is, is a lighthearted adventure involving pirates, evil magic keys, dungeon-crawling, and world-saving. Alundra 2 doesn't really have any ambition to provide more than that, and if you expect it to do so (likely by expecting it to live up to Alundra 1's standards), it's natural that you'll be disappointed and dislike the game. This is, for once, a real case of a sequel that should be judged by its own standards and not by those of its predecessor.*
And by its own standards...Alundra 2's alright. In lieu of deep issues and emotional depth, Alundra 2 goes for a touch of the goofy, keeping itself amusing. You're never particularly invested in or worried for its characters, but they'll make you chuckle on occasion. The events you'll witness aren't exactly inspiring or particularly novel, but they're fun enough and even quite humorous at times. It's a casual RPG, but for being such, it does it well, I think, for it knows when to throw in a bit of humor, and often you'll be caught off-guard by it enough that any cynicism you have won't have caught up by the time you let out a guffaw. There was one scene in particular in the game that made me laugh out loud, the one that shows how the king has been replaced and in what way this illusion is maintained--it basically boils down to a wooden king doll sitting in the throne with a dude hiding just behind said throne, who, when needed, reaches around to lift the king's arm in a commanding way, or adjust his head. This bit of zany humor is portrayed with just the right timing and attitude that I found it to be uncommonly funny.
I also think it's worth noting that even as a name cash-in title, Alundra 2 really isn't as bad as all that. It sure as hell isn't the only RPG to transparently use a name to help sell it, and as far as that goes, I've seen much worse. Remember Grandia 3? That game had even less to do with the series it stole its name from, making it another obvious case of adopting a name for marketing purposes, and it flat out suuuuuuuuuuuuuuuucked. Maybe Alundra 2 doesn't live up to its name and maybe they didn't try for too much more than a generic adventure with it, but at least it wasn't outright heinous, so it's still a step above its name cash-in peers.
The game sure as hell isn't without its flaws, of course. As I mentioned before, the control mechanics are pretty bad, and, though it doesn't matter much, it's quite strange that Alundra 2 would look so amazingly messy and ugly when Alundra 1 actually had a graphical presentation of good quality. The challenge factor of the puzzles is much less than Alundra 1's was, although that isn't necessarily a bad thing to some players (like myself), as Alundra 1's puzzles were sometimes way more difficult than they had any right to be. And hey, I wouldn't be me if I didn't frown on the game at least a little for not striving to do better with its story and characters. They may be amusing, but you can have a game that's both amusing AND has good characters and a meaningful plot--Disgaea 1 and Okage: Shadow King managed it, no problem.
Nonetheless, the overall package of Alundra 2 is fun enough, and though it's not very impressive, it at least knows this and doesn't try to convince you that it is, the way most uninspired RPGs will. And it does provide some good amusement all along its way. Alundra 2 isn't a great RPG, but I stand by the idea that it's at least a decent one, an enjoyable one, and I don't think it deserves the bad rep it has.
* I run into this argument fairly often, most notably concerning Chrono Cross, and every time someone has brought it up, it's annoyed the crap out of me. Because yes, Chrono Cross does suck enormously when compared to Chrono Trigger and as a sequel it's absolutely goddamn fucking awful. But if you don't compare it to CT, it STILL has an incomprehensible and outright stupid plot, a lousy and mostly superfluous cast, and so on. It is STILL absolutely goddamn fucking awful, taken alone or as a sequel. But its various defenders will, in a desperate move to at least appear like they have a legitimate stance, insist that anyone detracting from Chrono Cross MUST be doing so SOLELY because they're unfairly** judging it by the standards of Chrono Trigger. This tends to be the tactic of everyone I see use this argument when defending sequels. My point here is that Alundra 2 is, I think, one of those rare occasions where it actually is true that it's decent not by comparison but by its own merits.
** And why, might I ask, is it so unfair to compare a sequel to the original when it is clearly meant to tie in and build off of the original? It isn't like CC is detached from CT like Alundra 2 is to Alundra 1. They're connected by vital plot events, occur on the same world (more or less; that's always a gray area with time- and dimension-traveling stories), incorporate several of the same characters...obviously you should judge a game by its own worth, but when it derives a significant part of the qualities you're judging (plot and characters) from a predecessor, how it incorporates those aspects should be a consideration, too.