Karnov/Stage 4

The arcade and NES versions of Stage 4 are quite different. Both walkthroughs are described here, arcade first, and NES second.

Arcade walkthrough

 * As soon as you begin the stage, you will see a flame tile high up against the outside of the cavern. Use the ladder to collect it.  As you approach the entrance of the cavern, knights will appear to attack you.  Midway through the entrance, your mask tile will blink if you have one.  If you use it here, you'll see a few power-up tiles and K marks (shown right), but they may be more of a distraction than anything else, so think carefully before using it.
 * Through the entrance, you must make it safely over and under a series of volcanoes. The volcanoes spew fireballs, but they flash briefly before they shoot to give you a warning.  The volcanoes that face down shoot out a concentrated group of fireballs, while the volcanoes facing up shoot fireballs that spread out.  The safest place to stand when an upward volcano shoots is right next to it on either side.  The fireballs that it shoots will not hit you if you stand there.  Make your way through the volcanoes to the end of the tunnel.
 * When you reach a series of three conveyor belts, there is a slight detour you can take if you have the shoes or a ladder. If you use the ladder, you will not be able to take full advantage of the detour, so it's better to use the shoes.  Activate the shoes and jump up to the highest conveyor, where a ladder takes you up to the section above.

Detour

 * When you reach the top of the ladder, head left. A brown stone thrower will appear.  Stand one step below it and destroy it.  Then stand on the ledge where it stood, and your mask tile should blink.  Activate it and you will see a large number of power-up tiles appear (shown right).  Your shoes should still be active, so you should have no problem jumping up to collect the tiles and the K marks that line the ledge above.
 * There will be another brown stone thrower to the right of the ladder. Destroy it and advance to the right.  When you reach the ledge, the wings tile should begin blinking.  If you activate it, you can fly out to the right and find a huge cache of tiles (shown left).  Collect as much as you can.  Then you can choose to fly down and resume the rest of the stage, or fly farther out to the right until the end of the stage and fight the boss above ground.

Stage end

 * If you skipped the detour, or flew down with the wings, you will continue right past the conveyor belts. A brown stone thrower will be waiting at the end of a long platform that was preceded by a series of smaller platforms with K marks on them.
 * After you destroy the brown stone thrower, you should consider dropping to the floor below if you have collected the trolley power-up. If you have, it will begin to blink when you stand on the gray railway.  Activate it, and the trolley will appear.  Then you can jump on it, and control its movement with the joystick.  As you drop down the rails, enemies will appear and the trolley will obliterate them when they connect (shown right).
 * You can safely ride the trolley all the way down to the end of the stage, and even incorporate the trolley into your strategy against the boss. If you did not have the trolley, it is recommended that you stick to the series of platforms higher off the ground.

Boss: Spider Woman
The spider woman will drop down from the sky if you approach the end of the stage from the ground. While her attack isn't particular complex, it is difficult to dodge if you attack her too aggressively. Like most bosses, the spider woman will shoot at you when shot, and it will also fire intermittently on her own. Employ the strategy of shooting at her at the peak of your jump and running away from her shots until you are forced to leap over them. If you happen to approach her from higher up, she will cling to the wall behind her and position herself in order to attack you. While she can't approach you, she's almost more dangerous in this fashion since she is more likely to shoot upward at you and this can be harder to dodge. It's safer to take her on from the ground. If you used the trolley to reach her, you can actually jump back on the trolley and ride it to the left to escape her attack. Then return to attack her when it's safe.

NES walkthrough

 * In this version, the fourth stage takes place on an icy mountain with many paths that can be bombed open to reveal hidden passages. From the start, you will see a fire breathing demon that you should shoot at from across the way.  As you proceed right, small winged demons will appear.  When you are almost all the way across the flat section, jump up to make a large number of bombs appear (shown left).  Collect the bombs before continuing.
 * After collecting the bombs, you can put them to use by blowing open a secret passage in the side of the mountain (shown right). Before doing so, however, you may wish to scale the mountain a bit in order to collect a mask, a Clapper, and a boomerang tile.  To start the passage, the first bomb must be placed on top of the opening.  Then subsequent bombs may be placed on the ground.  Unlike the arcade version, bombs do not harm Karnov, so you may safely stand on top of the bombs as you wait for them to explode.
 * Once the passage is created, you will be able to enter a cavern whose opening is protected by small volcanic eruptions on the floor and ceiling. Navigate safely through them while avoiding the fireballs that they emit, then begin collecting the myriad of tiles that await you on the other side.  Before you climb a ladder, you will see a cache of tiles on the other side of a wall, but you cannot get to them from here.  Collect the remaining K marks, and place a bomb at the end of the tunnel to blast an opening to the ladder ahead.
 * Climb up the ladder. (Note that if you arrived here from the top of the mountain, you cannot bomb the wall open from the right side.)  Continue right, and remove the brown stone thrower.  In order to collect the cache of tiles that you might have seen underground, you must begin bombing the floor below a ladder tiles (shown left).  After you reach the floor, bomb the wall to the left to reach the tiles, then bomb the wall to the right to reach the ladder on the other side.
 * At this point, it is recommended that you climb the ladder and take the high path to the end of the stage, as it is considerably safer, and offers better tiles. Climb the ladder and scale the next mountain ahead of you.  Collect the boomerang tile on the way up (shown right), but watch out for a brown stone thrower.  (If you climb down the ladder at the peak of the mountain, you can use a bomb to reach another passage to the end of the stage, but you will miss more good tiles, so it is not recommended.)
 * Beyond the peak, watch out for two more volcanic erupting mounds, and collect the shoe tile with your ladder if you wish. Shoot at several strong men who advance on you as you walk through the passage.  Jump up to collect the wing tile, and watch out for more small winged demons.  Before you reach the large gap, you will have to defeat a golden robot.
 * You will see bombs along the ceiling, but they are hard to get to without using jump shoes, and aren't worth the effort. Watch out for the bats that appear, and jump straight across the gap to the floor ahead.  You probably won't reach the floor, but you will be able to safely land on the ladder in front of it.  Walk ahead to encounter the stage boss.

Boss: Spider Woman
The boss in this version is the same as the boss in the arcade version: the spider woman. She is substantially easier, however, in this version, simply because she is unable to fire projectiles at you as frequently as she does in the arcade version. Therefore, your strategy should be the same method of firing upon her as rapidly as you can, stopping only to turn around and run out of the way of the bullets she fires. If you can safely jump over them, or jump in the air to lure her fire away from where you are standing, do so. Never stand in place just to get a few extra hits in or you will likely get hit. In this version, you can even utilize the shield to block up to five of her shots, giving you a greater chance for success. However, the boomerang is not a good choice of weapon against her.