A fun adventure, which is worth exploring.
Rogue Galaxy starts off strongly with some interesting events which will tie into the ending, but after the first few hours, the game slows down and you start encountering understated events which seem somewhat insignificant. Although, during the last third of the game, it is understood that these events were connected to the main plot from the beginning. During the middle, the narrative is developed more effectively with major key elements being revealed which will lead to the abstract if somewhat predictable conclusion. Overall, the narrative seems to have some pacing problems with not much happening during the beginning, and a lot of information being thrown at you towards the end, to try and tie all the events together. Although the story may not be particularly original, it gets the job done by encouraging to continue the game.
The battle system in the game is a real-time battle system, and at times it can be extremely fun. There are random battles in the game, so expect to encounter enemies every now and then, although the game does not take you to a different screen when monsters appear, thankfully. The encounter rate can be rather unnerving sometimes, especially when you're trying to progress quickly through an area, and you encounter monsters every 7 sec or so. During battles you use X for regular attacks, and O for jump, which is required to hit some aerial monsters. The abilities in this game are learned through a pre-determined through a grid known as the Revelation Flow. Throughout the game you will acquire items from monsters, chests, and item shops which can be used to reveal new skills for characters. There are no healing spells, so you will be required to always have a good amount healing items, since AI team members seem to lose HP rather quickly and die easily even in random encounters. Overall, the revelation flow gets the job done, but it is nothing new, and some may find it rather difficult not to compare it to FFXII's recent license board, which provides a greater amount of freedom when developing characters' skills. The battle system stays fun most of time due to its fast-paced nature, but it can get repetitive since you start realizing you rely on the same two skills during random encounters or even boss battles.
The production values in this game are great fortunately. The graphics provide some of the best artistic design on the PS2, and probably the best cel-graphics seen on the PS2 besides DQVIII. It is quite impressive how Level 5 managed to make almost every dungeon and planet almost completely seamless with very little load times, although some freedom in exploration is sacrificed, since environment aren't as endless and huge as in other previous PS2 RPG's. The CG cutscenes presented in the game are gorgeous and contain a rich color palette and a lot of detail. The soundtrack in the game is well done overall, and fits the situations and different environments you will explore throughout the game. The voice-acting is exceptionally good, with spoken dialogue always lip-syncing, although some moments are a bit too melodramatic.
Rogue Galaxy is a lengthy adventure, although I think it depends on your grinding preferences how long it will take for you to complete it. The game took around 33 hours for me to beat, although I have heard that the most people took around 40+ hours to complete. It also has a good amount of replay value since an extra planet was added for the American version, to compensate for the delayed release. In the end, Rogue Galaxy is one the last RPG's for PS2 worth owning, and you should give a try for its excellent production values and fun battle system.