To progress through this skyscraper, you need to move up. This section is full of soldiers along with laser turrets, which move up and down or left and right. They can be hard to spot before it is too late, but they have to wait a second before firing. You will have to use some of the turrets as platforms to get higher.
Many of the soldiers are placed so that their attacks will knock you down, and it is very easy to fall quite a distance. As you get higher into the building, ninjas start appearing also. Once you make it to the roof, there are just a few more ninjas to take out before finishing this section.
The next section is on a freeway. You can alternate between being on the freeway itself or on some platforms next to it by somersault jumping, similar to what happens with the fence at the start of round 3. The freeway itself contains many kunoichis, but another problem is the cars -the green ones can't hurt you, but the red ones can. If you aren't on the freeway, you'll have to fight some soldiers.
Off the freeway there are many platforms to jump from, but be careful as one mistimed jump means instant death. Try using a shuriken spray to take down the many kunoichi near the end of the section.
The boss of this round is a massive armored vehicle, which carries a ballistic missile. You don't have to worry about the missiles, instead, you need to destroy three red weak spots on the vehicle itself. These weak spots pop out from under cover for a few seconds, and are protected by cannons. The other threat is the electric sparks which move around the vehicle -they are small blue spheres which you'll have to jump over.
The more weak spots you destroy, the more difficult it becomes, as the electric sparks will get faster and faster. Once all of the weak spots are destroyed, the vehicle will start to explode.