the ARMS race.
Filgaia is a dying land and they are trying to save it through ARMS: weapons of destuction used by ancient civilizations called elws.
so what's different about this installment?
the BATTLE SYSTEM.
first of all, the game goes back to the original WA where not all playable characters use guns(ARMS) but there are actually swords, and staffs and the like. They also bring back the use of MP (magic power/point)
But what's so special about WA4's battle system are the hexagon. Basically, you are given 7 hexagonal spaces to move about and 3 of those spaces have elemental characteristics to it that really make you utilize strategy, and proper character formation depending on the enemy, how many there are, and their elemental weaknesses.
It's a complicated battle system to get used to at first, and can sometimes make a battle challenging, but it can be easilly get used to and it makes each battle different and fun.
other things that are new:
-the individual tools that each character had especially for them in the previous WAs is gone, instead they provide you, on the field the nessasary tools to complete a dungeon
-you can jump, slide, climb which almost makes the game a puzzle/platformer type game.
-voice acting (which is not that bad... but most of the time, we can do without because most dialouges can be disregarded)
overall, its a good game and is a good rpg if you decided not to play grandia 3 or decided not to get wild arms: alter code F which is a PS2 remake of the original WA for the psx.