Level 12. Bath House

After Lo Wang's opening line, kill the enemies ahead and turn left.

Continue until you see a green truck with female ninjas on top. Blow up the tubes to destroy the ninjas and the truck.

Dive into the water beneath the destroyed truck, swim forward, and blow up the vent on the other side.

Go through the vent and resurface inside a bathroom. Kill the ninjas inside.

Head to the pool. Kill the ninjas there and dive into the pool to find an opening.

Enter the opening to find a missile launcher and a switch that opens bars to the left.

Go through the bars and pick up the blue key.

Return to the pool area and exit. Head to the counter and kill the enemies there.

Go upstairs and kill the two Coolies. The blue key door is to your left.

Use the blue key card on the door and enter. Kill all the rippers inside.

Locate the generators; one contains the yellow key, but it's inaccessible for now.

Follow your compass (minimap (the small circular map in the bottom-left corner of your screen)) until it reads North East. Go to that corner and turn around to find a switch below.

Hit the switch, and something will rise up. To the left of this switch is a hole with water.

Dive into the water and look for a small hole. Look through this hole to see a spinning switch.

Shoot the spinning switch to activate the generator, granting access to the yellow key.

Surface and exit to retrieve the yellow key.

Head back outside the blue key door and go upstairs (below the sign "Gold Card Members Only").

Use the yellow key on the door and proceed. To the left is a gate requiring a red keycard.

To your right, check the blue towel to reveal a Guardian Head and sticky bombs.

To the left of the blue towel is another pool with a switch on the side. Hit the switch to lower the water, revealing the RED KEY and a Riot Gun.

Pick up the RED KEY and use it on the gate.

Go through the gate and kill the brown ninjas shooting from the pool below.

Hit the switch behind the grey panel for a tool kit.

Make your way back to where you started the level, near the green vehicle.

Repair the green vehicle.

Use the repaired green vehicle to blow up the crack on the silver door.

Go through the silver door and kill the Coolie inside.

Check both lockers for a gas bomb and a smoke bomb.

Hit the end level switch to finish the level.