Harmony of Dissonance stays true to the exploration that makes other Castleroids great, though it isn't without flaws.
Harmony of Dissonance keeps the RPG based levelling system of Symphony of the Night while also allowing for equippable items. Throughout the game, various relics are collected that help Juste progress through the castle. None of these relics are anything astonishingly new, but they're as fun as they ever were in Circle of the Moon or Symphony of the Night.
The gameplay itself is much like that of the previous GBA game, Circle of the Moon, though the DSS system has been swapped for a simpler magic system that combines various spells with the standard Castlevania assortment of subweapons. These combos make for some interesting gameplay and strategy, though the system doesn't offer nearly as much diversity as the DSS system did in Circle of the Moon.
Backdashing and forwardashing have now made the main character much more agile than in previous Castlevanias. These new dashes may be spammed repeatedly to traverse great distances in the castle. This is a welcome addition especially since Juste seems to be a bit on the slow side and backtracking is frequent. I myself don't actually mind backtracking in my Castlevanias as it encourages the use of new skills in previously explored areas, but many people will find the frequent backtracking a tedious and boring affair.
The graphics are rather well done with many well-detailed environments, though some backgrounds are rather dull in appearance. The character animations also look rather clunky at times which is a bummer considering you'll be staring at Juste for the next 10 hours. Juste also has an eerie blue glow around him which made me wonder whether the animators did this to help distinguish him from the backgrounds or whether Juste had simply gotten to close to a radioactive waste dumpsite.
Unfortunately, the enemies seemed rather dull compared to those in previous Castlevanias as well. Circle of the Moon included bosses of epic proportions in the form of the Adramelech and the Zombie Dragons, but many of Harmony of Dissonances bosses honestly feel like glorified skeletons. This is really too bad considering variations on skeleton enemies make-up a huge chunk of the bestiary. Many of the bosses just feel the same and offer very little challenge at all.
The sound effects are alright, but the music in Harmony of Dissonance wreaks of dissonance. This is easily my least favorite soundtrack of the Castleroid installments which is a disappointment considering Circle of the Moon had some real catchy tunes.
All in all, the gameplay is solid. It feels like Castlevania which is never bad. The RPG elements are still here along with a heavy emphasis on exploration. If backtracking isn't your cup of tea then maybe Harmony of Dissonance isn't for you. Harmony of Dissonance doesn't fail in its representation of the franchise, but it isn't Symphony of the Night or Circle of the Moon by any means. It's an excellent great game, and any fan of the franchise will love it.