A much better game than what its first impression shows. Quite simply, the creepiest RPG I've ever played.
This game is very creepy, down to the character designs, the environment, and the music. Sometimes there's nothing like a twitchy Manikin (a human-like creature created from mud) to send chills down a player's spine. Also, the main character is always traveling alone, save the demons that he has recruited. He is usually alone in dungeons as well, save for the occasional floating blue spheres of light, which are spirits.
Obviously, the battle system is the highlight of the game. There are about 4 elements (Fire, Ice, Elec, Force) and a few other attack types that are not really elemental, like Physical, Expel, Nerve, Death, etc. The trick to coming out of battles unscathed or not seriously wounded is to figure out how to best take advantage of enemies' weaknesses. Each battle starts with the number of actions equaling the number of fighters present. If an enemy's weakness is hit (say using Agi against an ice demon) then the player gets one extra action per turn. However, if the player misses, or uses an attack that is either voided or absorbed, then an action is lost in that turn.
Bosses usually take a trial-and-error approach, as players usually go in with elements that are weak to their attacks without knowing. That's why it's always good to save whenever possible. If unlucky, even a normal enemy can wipe out the party with a few lucky hits. Regardless of other demons in your party, if the main character dies, it's game over.
One thing to note is that while healing items are abundant in the game, MP refilling items (like Chakra Drops) are not. It's always best to go to Fountain of Life for healing and save those drops for bosses.
Another fun system in the game is demon recruitment. While some demons are only available through fusion, most of them in random encounters can be persuaded into the player's team with items and maccas (the currency in the game). Assuming if the main character's level is higher than it of course. The requirements and procedures are random, and there is usually a question at the end of negotiations. If the answer is deemed satisfactory, then the team has a new member. However, sometimes even after giving away a lot, the demon still will not join, and will go away by giving you usually a crappy item. Also, sometimes they want to join on the own, so nothing is ever predictable.
Overall, this is a very challenging yet rewarding game. Players can spend much time hunting down demons and fusing them together in different combination. Whichever way the game is played, everyone can find something appealing in the game.