Great game. I now know why Fire Emblem is one of Nintendo's greatest series.
The game play is similar to Final Fantasy Tactics, with battles taking place on gridded map. During battles you normally are trying to wipe out the enemy forces or defend a certain square from being taken. Each unit has a corresponding job, such as Swordmaster, Paladin, or Mage. When a unit reaches level 21 it class changes, meaning it gets a new look in battle and its stats get a significant boost. After class changing a unit's level will drop to 1, but don't worry about that because it really means level 1 of its new job, but level 21 overall. The only bad part about the game is if a unit dies in battle they are gone forever. If you want to keep every unit alive until the end of the game, you'll probably have to reset the game many times.
This game is for people who like strategy games or for those who like games with a story, but don't want to have to deal with the ridiculous grinding periods that a Final Fantasy-type RPG usually brings at some point during the game. The game will take you awhile to beat, it took me a little over 30 hours, but if your willing to put in the time and have some patience, the game is very rewarding at the end. The best part is that after you beat the game, you can load your file into a new Fire Emblem: Radiant Dawn (Wii) file. In Radiant Dawn, every character that reached level 20 and maxed out some stats in PoR will receive a stat boost at the first time you play with them.