I wonder what feature of this game made me like it so much...
Yes, the story is very cliché! Evil empire, good kingdom, war, good guy gets a powerful weapon to defeat the empire, bad guy gets a weapon as strong as the good guy's weapon. Final fight, boom!
The good part is that there are many paths and endings. You can defeat the bad guy, or you can join him (not because you want to, but... well I won't spoil it :P).
Another PRO of this game is the music. It's really beautiful. And Zulwarn's theme is just perfect (check out the song "Hole").
The game itself is actually a simple turn based strategy RPG. You can't "power level", since there are no battles between the missions that makes the story progress.
Later, the difficulty can be a bit hard. You'll have to reload your saved game a few times, and try new strategies to beat your enemies. Don't get cocky just because you got the Ultragunner ;P
The graphics are typical of a 32-bit RPG. Actually, it could probably be released for SNES, if it weren't for the battle cutscenes. You choose an attack, your opponent chooses his reaction, and the cutscene begins. A 3D scene showing you and your enemy fighting, 1v1, from side view, like in a fighting game. It sounds so simple, but it's so catchy (I couldn't skip a single battle scene during all the game!).
Overall, this game is great. 10/10 in my opinion. You should definitively buy it, or at least rent it.
Just a note though: it can be a bit hard to find this game in stores (even more now, since PS1 is long dead).