First up is your action bar. Each character has a limited amount of time to complete his or her turn before it ends. But within that turn, you can move freely about the battlefield. Each action, whether it is an attack, a spell, or a simple movement depletes the bar even more. As your party level increases, the planning time you have decreases, special attacks deplete more of your meter, and other changes are made until battles are frenetic, tactical scherzos.
Battles are an enjoyable mix of turn-based movement and real-time combat.
Then you have a whole other can of worms: light and dark. If you're standing in the light, you have a different set of skills available to you than if you are standing in shadows. For example, newcomer Serenade can execute a party heal when she is standing in the shadows but a spectacular-looking ranged attack when in the light. Furthermore, these abilities may change depending on how close you are to your enemy. And if that wasn't enough, your enemies can take advantage of the light and dark as well, going so far as to shape-shift when moving from one to the other. Eventually, this system gets complex because enemies may cast spells on you that envelop you in darkness, or you might use items that surround you in a glow of light. And some weapons are more effective in the shadows than in the sun.
There's also a real-time blocking mechanic, where a well-timed button press can block an enemy attacking from the front or even execute a counter attack. In the later portions of the game, blocking can make the difference between success and failure. But it's not easy to block, so don't expect to mash the block button when you're on the defensive. You have a tiny smidgen of time, so you are constantly on your toes, even when it isn't your turn. All of these dynamics result in a constant tactical repositioning of each character depending on where you stand, where your enemy stands, whether you're attacking it from the front or rear, and other factors. It's literally the best of both worlds, combining the strategy of turn-based battles with the frantic immediacy of real-time combat.
Most of the time, the system is terrific, and the challenge ramps up considerably as the game progresses. But there are some small issues with it. Creatures cast their own shadows, so if you are in one of them, you obviously only have access to your shadow skills. This is usually a great strategic element, but because monster animations cause the shadow to move as well, you could be caught on the fringe of a swaying foe, watching your available actions jitter back and forth. You could end up using a different skill than you intended or wasting some of your precious action bar on moving to another location, thereby getting less time to attack the enemy. It's also worth noting that the enemy artificial intelligence is inconsistent. On the one hand, monsters are quick to figure out which party member is casting the healing spells and will focus their attacks there. On the other hand, they don't quite know how to handle objects on the battlefield, sometimes charging right into a boulder and doing the hokey pokey before turning themselves around.
Serenade gives thanks for her experience points.
Other frustrations are minor, but they still come up from time to time. Your journey is highly linear, so don't expect to spend any time doing side quests or gallivanting about the countryside to check out the sights. Another odd element is Beat's photography skills, which allow you to take pictures during battle and sell them for a tidy profit. The problem with it isn't the concept--because it's a great way to allow the party to earn some money--but that you can make a serious load of gold this way. So if you take the initially powerful Viola and Allegretto into battle with Beat, they can mop up enemies while Beat snaps countless photos. It won't take long to accumulate more funds than you know what to do with, and it eases the challenge considerably because you can load up on floral powder or healing cookies. And interestingly, for a game featuring a famous composer, music isn't integrated into the gameplay itself, aside from a minigame that lets you play bits of music with various friendly townsfolk. It's nice that you can listen to music clips that you unlock, and characters and towns are all named after musical terms. But it's always subtext and doesn't often come to the forefront.
The new dungeons are quite good and help extend the length a bit, though you should be aware that one of them is only available to you once you complete the game, which clocks in at under 35 hours. Even with the new content, though, Eternal Sonata is much the same game as before--which makes it one that you should play, if you haven't already. Its lovely, gentle story and fun combat make for a heartwarming journey that will both draw you in and make you wish you didn't have to leave.