Oni features awesome combos, such as Haymakers, Devilry Kicks, and Crescent Punches etc. The in-game graphics are great, the ammunition, once fired, looks fantastic with just about all the guns. Most of them leave nice looking trails, which really spice the game up. ONI features a fairly involving story that links everything together. There is a range of baddies, some just ordinary lab technicians, and some robot-like fiends that are trained to kill.
Most enemies wear gas masks or advanced biological helmets.
Which ever you come up against they will usually be hard to beat, as the game gets harder as you proceed.