Level 5. Rising Son

Grab the Uzi and portable medikit on the starting boat.

Ride the boat until it sinks, then enter the hole in the left wall created by an explosion.

Kill the ninjas inside and grab the Uzi ammo.

Walk up the path to the bridge, cross it, and pick up the other Uzi.

Kill the ninjas on the other side.

Replenish health in the dojo room.

Warning: Stepping on the table with a bowl in the dojo room opens a secret passage between the two dojos, revealing a grenade launcher.

Check cabinets for items like caltrops.

Go through the door and use the turret to kill ninjas shooting from the water on the right.

Dive into the water where the ninjas were and pick up sticky bombs.

Find a crack in the wall and use the grenade launcher to blow it open.

Go through the opening and kill the enemies. The right path is a dead end with various panels offering items.

Head left and through the door, taking down brown ninjas shooting from the left.

Go through the next door and defeat the guardians.

Use the statue to reach the ledge with rail gun rods and armor up high.

Return to where the brown ninjas were and jump out into the opening facing a waterfall.

Take the eastern path and follow it to find the GOLD KEY.

Warning: Hitting the gong up top triggers an opening to your right, revealing a missile launcher.

Return to the area with the two guardians and go through the other door.

Kill the rippers along this path.

Next to the silver keyhole, find a crack and blow it open with explosives for a fortune cookie.

Use the GOLD KEY on the gold key door nearby and go through.

Kill the guardian attacking you inside.

Go through the next door, avoiding fireballs and blowing up barrels.

Take out the Coolie and continue past the Buddha statue to a small bridge.

Jump to get the SILVER KEY hanging at the top.

Use the silver key on the door near where you found the fortune cookie and go through.

Solve the floor switch puzzle: Step on the blue and yellow floor switches and hit the green switch. Then, step on the blue and red floor switches and hit the purple switch. The door will open.

Go through the door and down the path, killing rippers.

You will enter the Serpent's Lair.

Fight the Serpent boss. Stay behind columns for cover (press the cover button to crouch behind walls or objects).

Warning: Do not let the Serpent knock you into the lava.

Kill the Serpent's Accursed Heads to avoid gas bombs.

Once the boss is defeated, hit the end level switch opposite the entrance to finish the level.