Radiant Dawn is a worthy entry in it's series, though a few minor missteps prevent in from reaching it's potential.
Radiant Dawn's gameplay is mostly the same as any other game in the series. It is a tactical RPG, with player's characters being able to gain experience in battle. Players move their army along a square-based grid, defeating enemies, obtaining items, and accomplishing other goals- such as having their army's leader claim a point of importance. Radiant Dawn is more difficult than just about any other game in the series, which is fine, though it leads to a bit of a luck basis determining success or failure for players who aren't able to comfortably win their battles, which is no easy task in Radiant Dawn.
Radiant Dawn also features a huge number of playable characters, which in turn leads to a huge number of possible strategies, and a lot of replay value. The game also allows the player to customize their units with a variety of skills, which further adds to the game's replay value. Seeing as Radiant Dawn is by no means a short game, this gives players the ability to play and enjoy this game for a very, very long time.
An interesting gameplay change that Radiant Dawn makes is having the player control several different armies at different points in the story. This helps increase the difficulty of the game (though this is not necessarily a good thing), and helps Radiant Dawn feel like it is it's own experience overall.
Radiant Dawn's presentation is decent as well. This game features a high-quality soundtrack, with a large number of different musical tracks used for a variety of situations in the game, though the game's graphics aren't much of anything special. Radiant Dawn uses somewhat interesting, though not very pleasing character models, though the game's environments look much nicer. Of course, any graphical problems that don't interfere with the gameplay in this situation are a minor flaw at most.
Radiant Dawn is not without a few more noticeable flaws though. These mostly consist of a few changes from the series' norm that I personally do not find to be entertaining. The largest of these are known as "mastery skills". When a unit reaches a high enough level to "promote" to a third-tier class, they gain a rather overpowered ability, which takes up quite a bit of the unit's capacity for learning skills, and cannot be removed. The biggest reason why I dislike these skills is that they activate almost completely at random, which not only results in an increased luck basis, but can also make it more difficult to level up some of your weaker units by weakening enemies with someone more experienced before letting your weaker character strike the final blow and gain a greater amount of experience than they would have had they not defeated their foe, as these skills will nearly always defeat any unit that is hit with them.
Another misstep is the changes made to the support system. What used to be a means for a great amount of character development in the series executed my means of conversations between characters has become little more than battlefield chatter. Fortunately a lot of Radiant Dawn's returning characters have already been fleshed out sufficiently by support conversations in Path of Radiance, though fans of the new characters may feel like their favorite characters could've used more depth, especially when the characters in question are less important to the game's plot, and those who have not played Path of Radiance will not be able to learn as much about the characters as they may desire to.
Radiant Dawn has a plot that does not reach the levels of quality that the series is known for, due in part to the lack of character development, and partially due to weaker dialogue and plot. I won't get in to an explanation of this here in order to avoid spoiling anything here.
Radiant Dawn is a strong entry into an excellent franchise with loads of replayability, but a few missteps prevent it from reaching the level of quality of it's predessesor in Path of Radiance. However, it is still more than a worthy title for anyone looking for a high-quality strategy game, and it is perhaps the best strategy game the Wii has to offer.