I finished the game (I think I'm the only Evilborean who stuck with it, as apparently most people didn't like the idea of turn limits or a wacky animu take on French history). My thoughts are as follows:
Turn limits: Probably the most controversial and disliked point of the game, at least from what I've read here, but to be honest, I actually was never faced with a situation where I had to worry about using up all my turns. There's actually a very solid, legitimate reason for turn limits within the game, and it has to do with the battle system's design. You gain MP every turn, and Jeanne gains transformation points every turn as well...if there were no turn limits, the game would simply turn into turtling, where you just hold off the enemies until you've built up enough MP to unleash your most powerful attacks. With turn limits, you're forced to strategize while moving forward.
Unified guard: This actually adds a lot to the gameplay and makes you think of your team as a unit As in a real battlefield, you never want to stray too far from the group because it'll make you easy prey for opponents...in Jeanne D'Arc you are actually rewarded for sticking close to the group by having the "unified guard" ability activate whenever you're attacked. Probably the toughest battles I ever had were those where my team was split up on different parts fo the map, and the very first thing I did in those battles was to regroup.
Skill stones: These are great and allow a good degree of customization for your characters abilities - skill stones give you class-based attacks, magic spells, innate abilities, and raise your stats. Eventually you'll be able to bind skill stones together to create new ones. This is a great way to experiment and to get advanced skills from early on in the game. Once you've found a formula for creating a particular skill stone, it's saved so you can check it later if you want to make that particular stone again.
Rock/paper/scissors: Represented by moon, sun, and stars...each character can be given a particular affinity, which makes them strong against certain enemy types but weak against others. I actually never bothered to use it that much, since giving a character an affinity requires a skill stone which takes up a skill slot and I wanted to keep them free for certain other things.
Combat: The maps are mostly very well designed and fun to play through...there are a few that are a bit too clever for their own good (there's an optional rooftop stage where you have to make bridges between roofs and your characters are all split up, making them easy prey for the archers that populate the level). There are a number of extra stages you can go through to gain better equipment for your characters.
Story: A complete joke. That's probably the only part of the game where I think they had a lot of wasted potential. A more serious take on the Jeanne D'Arc story and the Hundred Years War could have made for an amazing game. Instead, they went with the most cliched and stereotypical animu crap imaginable - from the heroine's village burning at the start to being succesors of five legendary heroes, to finding mystical objects of great power to defeat the evil monsters who come from another dimension to enslave mankind. Every plot point is obvious after the first five minutes of the game - who in your group is going to betray you, who's going to live, who's going to die, etc. That said, the cut scenes are very well-animated and plentiful.
Graphics: It's Level 5, so of course they're beautiful. The other strat. RPGs on the PSP can't even begin to compare - I even think it looks a good bit nicer than Disgaea (going off the PS2 version), though Disgaea is the superior game.
Overall: A slightly above average game which is perfect for a portable machine like the PSP. A B- (but a real one, not a pity one like Willco gave to Transformers).
I'd like to see more strat. RPGs come out for the PSP as it seems to be a genre perfectly suited for portables...I wouldn't mind seeing a port of Saiyuki for it! Does anyone remember that game? Came out during the tail end of the PSX's life span.
