Shadow Warrior/Seppuku Station

Walkthrough
The game starts with two Zilla enemies jumping into your dojo. Quickly kill them. If you took damage, you can switch to your fists, and punch one of the training targets to regain health - this is free but slow.

When you jump outside, you will likely encounter Zilla forces to the left. Since you need a better weapon, look in the back of the white vehicle to retrieve an Uzi.

Proceed to the left, and engage Zilla on the way. You should reach the end of the corridor, where you can find a gold key. On higher difficulties, the enemies will hide behind the crates, and may even attack from the window overlooking the area. Regardless of difficulty, you will want to enter the room above to retrieve the portable medikit, as well as to reach the secret area for the grenade launcher.

The office overlooking the gold key has another Uzi, and a portable medikit behind the picture. The picture is raised by pressing a button behind the desk.

Gold Key Door
The gold key door is on the right path of the street, found on the building on the left. When you open this door, there are a few enemies, one of which hides behind the counter. You should obtain the riot gun, found by jumping through the window on the left wall.

Head through the baggage conveyor, which leads to a room with one Zilla grunt. To the right is a monitor, which you can use to control the yellow car found later. Using the monitor display, move and turn the car to the far-left corner, where you can retrieve the key later.

Backtrack to the reception area, then head to the left. Continue past the koi pond, and into the locker area. Clear out the enemies and head to the pachinko parlor, where you should find the silver key. If not, it would be on one of the cars in the track, and you'll need to head to the security room (described above) to move the car to where it should be. Also in this room is a fortune cookie secret activated by the ATM. You can also play on the pachinko machines to get a random item.

With the silver key, you can open the door leading earlier in the level, clearing any rooms you missed, and collecting items.

Subway
Head to platform 45 (opposite the Pachinko

Secrets

 * 1) In the starting Dojo, there is a locked door behind you.  Throw a shuriken through the door at the gong, then turn around to see the opened painting.  Reward: Nuclear warhead, two shurikens.
 * 2) In the gold key area, there is a lead you can use to reach an overlooking window.  If you instead jump across to the far wall and enter that window, you enter a red room.  Reward: Grenade launcher, Sticky bombs
 * 3) After the gold key door, there is a secret alcove raised above the ground.  To reach it, shoot the nearby garbage receptacle until it is close to the secret.  Jump on the trash can, then jump to reach the secret.  Although you can grab items without entering the alcove, you need to enter it to claim the secret.  Reward: Ammo, gas bomb.
 * 4) In the locker room between the pachinko parlor and Platform 45, there is an off-colour locker.  Activate it to open a secret door behind the lockers.  Reward: Missiles, and +100 armor
 * 5) In the pachinko parlor, look for an ATM and use it.  Turn around, and reach the secret that gets opened.  Reward: Fortune cookie (+50 health).
 * 6) In the kitchen, there is a set of lockers.  Open the right-most of the lockers.  Reward: Fortune cookie.

Although not tagged as secret, you will want to note the following:


 * A riot gun is found to the left of the subway reception. It is reached by jumping through the window, and is found on a pillar on the street.
 * The Pachinko machines can give out random items if activated.
 * The subway platform's center column hides a heatseekeer card.