Oni, with it's complex controls and difficulty level makes it a game that is only worthwhile for a few select people.
Oni puts you in the story of Konoko, a police officer working for the Technology Crimes Task Force. The TCTF was made futuristic organized crime and Konoko is one of their top officers. The story in Oni is pretty fitting in the anime genre as it gets more and more interesting and strange as you proceed in the game. It's one of Oni's more stronger points.
Oni's levels are long and and full of ways to sneak around, and plan your assault. They are also pretty generic looking. While Konoko herself looks pretty cool, the enemies and the levels could be used in any game and are lacking in graphic department (which is one of Oni's weak points). The level missions are also pretty generic, and this can drag the game down a bit. Thee usually involve taking out someone, or hitting a certain switch, or reaching a certain area.
Saving is done by passing through certain save points (you'll know when the game saves as you'll get a message), and doesn't allow for any saving on the fly. This makes some areas more harder then others, and can leader to further drag points.
Oni's best point is the controls. Oni features a very complex and deep fighting system that other beat em up games lack. It puts the full PS2 controller in use. Movement is by the left stick, camera is controller by the right, and most action commands are placed using the the top trigger buttons on the controller. Most secondary, and item use commands are on the PS2 facepad buttons. It's wild, and unusual and seems to go against the usual button placement in games. It'll confuse and turn off players in the beginning, and adds to the difficulty of the game. Even after training mode, it'll take you a few mre hours before you really get a full knowledge of the game's controls. After really getting accustomed to the game's controls, you'll be able to take on multiple enemies at once, and be better adapt to taking out enemies faster. The game allows you to do many things: fight in all directions, foll and dodge attacks, pick up items off the ground, and use weapons to take out your opponents. Enemies also have the ability to pick up weapons, which effects combat and adds a sence of urgency. You'll need to disarm opponents in order to take out the weapon-trotting enemies. Enemies will also try to make a dash for weapons on the floor, trying to get it before you get it. Weapons adds more complexity to this beat 'em up game, as it gives you the ability to fight enemies from a distance, and take on enemies that have weapons.
Graphically Oni had issues. it's not pretty, it's rather bland. Luckily, the animation in Oni is really smooth, and fluid, and fight scenes (with understanding of the controls) cna make for some beautiful action moments. Konoko looks and moves like a real person might, which adds to the fight scenes.There are some serious clipping issues, as characters can go through walls very easily. even live characters can get stuck on walls.
Oni can really be enojpyable and appreciated once you gain full understanding on the game's controls. It's just a shame that the uninteresting graphics, and missions, and difficulty of the game and controls are there to really turn off a player. Oni requires patience and time, which is something players aren't willing to give these days.