Joe heads towards an enemy base on his horse. The horse cannot somersault, but can jump very high. The only enemies in this stage are ninjas, who will keep dropping out of kites in the background. They will run forward and off the screen, and then appear in front of Joe. The other hazard in this stage is the wooden stumps that sometimes appear, that you'll have to jump over. You'll see a warning exclamation mark a few seconds before the hazard itself appears.
When the ninjas appear in front of you, kill them quickly or they'll jump up and start throwing shurikens. One possible strategy is to move to the right of the screen and kill them as soon as they appear, but then watch out for the stumps.
The sub-boss of this round is a powerful golden ninja, who can move very fast and throw spears. He will throw three spears and then move behind Joe. Jump over the spears and wait at the very left of the screen, as the ninja will come back. He'll do a flying kick that will miss, so just hit him with a shuriken as he runs off.
He'll then repeat this pattern. It is possible to destroy the spears he throws, but you'll have to throw shuriken pretty quickly and it is usually easier to just jump over them. The ninja doesn't take that many hits and will explode when killed.
The next stage takes place inside the base. Here you'll come across some new enemies, like the soldiers. The soldiers carry guns and will fire single rounds at you, whilst the other enemies are larger grunts with shields and boomerangs. These soldiers are stronger and can protect themselves from attacks, so try spamming the dive kick or use the somersault jump to get over them and then attack from behind.
This stage is fairly straightforward, just move to the right to progress. There are a couple of hidden platforms you can get to with a well timed jump in the middle of the stage, which have some item boxes on them. Towards the end of the stage a single soldier and boomerang soldier are waiting, kill them and move on to move to the next stage. You will be on an elevator platform, which automatically starts to ascend.
As the platform moves up, you will have to shoot down several soldiers who crawl along, along with some other troops who use bigger guns. After they've all been dealt with, you will have to make use of platforms and railings to keep moving up with the platform. Watch out, as you can die from being crushed if you stay on the platform in certain areas.
The enemies here are the soldiers, some of which are placed to knock you off platforms with their shots. Take your time and try and kill them by jumping and throwing a shuriken, and then move onto the platform they were on.
Get back on the platform when you can, as it will take you up to where the boss is. Move right to enter the next room, where you'll have to fight a flying supercomputer.
The boss will keep rapidly darting around the screen, and then after a few seconds will come to a stop and use an attack. One attack will have it send out four bombs, which will all explode and send out several pieces of shrapnel. You can try and destroy the bombs before they explode, but it is easier to just duck as the shrapnel won't hit you. Another attack will have it warp the space around it, causing the controls for left and right to reverse for a brief period. The boss will then move around the screen and shoot at you with several bursts of fire.
Finally the other attack it can use involves it firing a powerful green laser at the floor, in four shot bursts. As the boss moves around the screen, just keep throwing shurikens at it. It cannot be hit when it has a blue shield around it, which it will put up when using certain attacks. After the boss takes enough hits it will explode and crash into the ground.