Excellent, but I struggle to recommend it as it is right now.
This game combines all of the best features of Legend of Xenia 1 and 2, and really shows off how far you've come since the first entry in the series. Legend of Xenia 3D really takes advantage of the new perspective. Being able to jump over ledges and sidestep around slimes gives the game a sense of freedom, and despite the tiny resolution, there was never a point where I got lost and struggled to make progress.
Though I'm a little disappointed that Xenia's back on the beach looking for the three rusty keys, there's just enough new stuff thrown in alongside subtle improvements in pacing, writing and level design that I don't mind the retread at all.
Despite all of those positives, I can't beat around the bush any longer: the haunted wood doesn't work, and that's an area of the game that's essential to finishing it. Though I appreciate the attempt to make the area more atmospheric by darkening the environment, the whole thing runs in slow motion, meaning that attacks take longer to wind up and connect, movement feels slippery and you have to push your mouse twice as far to look around.
Compare how you move and slash your sword on the beach:
to how the same thing looks on the wood level:
looks about the same, doesn't it? That's because as I went to replay the game to get the footage, I ignored the valley of locks and headed straight east and it miraculously loaded the area with no lag at all. Regardless, I highly urge you look into it.