A.I. Breaker: Despite being a Badass Normal with a pimp cane and ability to take a lot of damage, Silverman (the boss of Stage 4) doesn't know how to counter crouch attacks (unless it's from Ninja, who's too big to avoid his cane).
Arm Cannon: This is Ninja's super move. He points his arm and a panel opens up for a small cannon to pop out. One massive blast later and no more enemies...
Attack Drone: 3SVO II are small white robots that move on the floor and fire lasers. They are short, making them slightly difficult to hit (Hint: throw them for massive damage).
Bowdlerize: The Kunoichi enemies were removed in the overseas versions due to Nintendo of America's stance against the depicting violence against women. However, instead of replacing them with sprite-swapped versions of the same enemy like Capcom did with the SNES versions of Final Fight games, they simply replaced all of their appearances with that of another enemy character (Saru).
Chainsaw Good: Chainsaw Bull (the Stage 2 boss) is a giant of a man with a yellow coat and fireman's hat, gas mask, and a chainsaw that he uses to cut through a steel door just prior to engaging you.
Charged Attack: Different from the standard variety, in that it charges automatically over time, but depletes completely if you get knocked down while it's recharging. Functionally, it's more of a Smart Bomb.
Determinator: The player-controlled androids are programmed for a single purpose: Kill Banglar. It's also the reason why they were forced to self-destruct after killing him, as their ability to think for themselves was not fully developed.
Difficulty By Region: The Japanese title has those skimpily-dressed Kunoichi enemies while the English versions replaces them with more short monkey dudes that sport Wolverine Claws. The monkey ninjas are shorter and can avoid more attacks, but the female ninjas dodge around a lot more.
Divergent Character Evolution: The Ninja and both, the player and enemy versions of Kunoichi, all have different designs, unlike the arcade original, where they were all head/palette swaps.
Elevator Action Sequence: You fight a bunch of enemies in an elevator just before the fight with Zelos, the seventh boss.
Elite Mooks: Several types. Saru the tiger-claw wielding trained monkeys can be Demonic Spiders if you aren't careful. Later, you encounter weird color-changing synthetic humanoids called Pumas which are also a pain, due to their extremely fast movement.
Flawed Prototype: The circuitry for the android ninjas to think for themselves was not developed properly, and their sole purpose was to destroy Banglar. Due to this, they had to self-destruct after fulfilling their mission.
Flunky Boss: Every single boss (except Yamori and the android twins) fights alongside their underlings. In the case of the Final Boss, flunkies are actually a good thing, as the only way to damage him is to throw his men into him.
Invisibility Cloak: Yamori (the Stage 3 boss), a genetic monstrosity with a skull for a face and clad in purple pinstripes, can cloak himself while he claws at you or drops grenades on you. You can just barely see him though, and he can still be hit while he's on the ground.
Kung-Fu Proof Mook: The Golems, which are tall bipedal robots with Eye Beams. They cannot be damaged from the front with regular attacks, however, the player can easily get around this by attacking their back, throwing them, or throwing somebody/something else into them.
Made of Explodium: The Mecha-Mooks, as well as certain environmental objects, and a tanker truck in the opening level. Also, the player when you die.
Made of Iron: The player characters are capable of withstanding knives, bullets, explosives, chainsaws, Ninja magic spells and a variety of other nastiness. Some of it can be forgiven due to them being literally made of iron metal.
Honorable mention goes to Silverman who, for being a more or less normal man, can take enough kunai-stabbing, scythe-blading, rocket-punching, arena-exploding punishment to drop the entirety of a neighborhood gang (and then some). While possibly beating up robots with a cane.
Name's the Same: Sort-of. The female enemies exclusive to the Japanese version are simply identified as "Kunoichi", the same moniker given to the female player character. Note that while the arcade version had Kunoichi enemies, they were simply palette swaps of the Player 1 character, whereas their counterparts in this game have a unique design.
Ninja: Duh. This game has Ninjas coming out of its ears. One character is even called Ninja, Kunoichi means female ninja and she looks and moves more the part, and Kamaitachi when written in a certain way means "sickle weasel", hence his wicked arm blades. His appearance is more Killer Robot, but he definitely moves like a Ninja. You fight a few of them too.
Spin Attack: Ninja can do this with his booster in the air, and with his Charged Attack. Kamaitachi does it as part of his regular combo.
Stripperific: The enemy Kunoichis you meet (in the Japanese version) are rather... impractically dressed. Probably the reason why they were replaced with more Wolverine-esque ninjas in the English versions.
Synchronization: Phobos and Deimos who share the same life bar. They take about twice the damage a regular boss can take, but hitting both at the same time would hurt them for double damage.
Tactical Suicide Boss: If Banglar didn't summon minions during his fight, you wouldn't be able to harm him via throwing said minions into the glass.