Keith Courage in Alpha Zones/Toxic Zone

Overworld
The sky of this Toxic Zone is fittingly a dark gray. As you make your way to the first house, you will be attacked by a few enemies, including the flying cats. Step inside the first house. As you head forward, the cats will stop, but little blue enemies and bouncing heads will attack from all sides. After a short distance, you will encounter the only major "feature" of Toxic Zone: pipes belching pollution into the air. Each pipe releases exactly three puffs of smoke before pausing for a while. Naturally the puffs of smoke are harmful to Keith and should be avoided. The cats will resume as you walk past several more, taller pipes until you reach the second house. Beyond his house, you will have to traverse over a spike filled pit using floating platforms, first horizontal then vertical, until you reach the other side and find another door. Continue to the right and you will have to walk through a field of low lying pipes, each puffing out pollution. Walk past them when they are taking a break in order to avoid taking more damage than necessary. Enter the next door beyond the pipes. With the Laser Sword in hand, continue to the right past one more inert pipe and step onto the hut to transport Keith to the Underworld.
 * The Prophet welcomes you to the Toxic Zone and advises you to look out for the Laser Sword.
 * The Wise Wizard offers to sell you more Bolt Bombs for 200 Coins.
 * Nurse Nancy will heal your wounds for 400 Coins.
 * The Weapons Master will offer to sell you the Laser Sword for 1200 Coins. Accept his offer.

Underworld
After jumping over a small set of spikes, you are only able to advance so far before you reach a wall and are forced to descend. This section plays a cruel trick on you, as it does not permit you to see the spikes just below the set of pillars that lead you down to the bottom. You must approach this section with caution, or you risk losing half of your money and Bolt Bombs.

After you safely drop down to the first sub level, you can only travel a short distance to the left before you are forced to descend once more. On this second sub level, you must advance to the right. Along the way, you will encounter a robot much like the ones you faces as the bosses of the first zone. There will only be one this time, followed by a strengthened Titan Guard. This particular Titan Guard makes a good candidate for repeated defeating until you obtain the heart that extends your health meter to seven hearts.

Beyond the Titan Guard, this sub level will dead end with a set of spikes before a wall. Find the pillars which lead to a small gray platform, wait for it to reappear, and use it to climb back up to the first sub level. Once you're back up, head right and carefully leap over any spikes you see until you can climb up the pillars that lead back to the surface via another gray platform.

You will be greeted with long floating skulls. From this point on, several enemies will be attacking you, so use your best judgment about which ones to engage and which ones to run away from. You must run quite a way to the right until you reach what seems like a drop below with a small gray platform off in the distance. Dropping down will only lead you to a dead-end where you must return back up to proceed. Instead of dropping down, leap from the gray platform to the higher ledge on the right and continue. You will see the same situation once more, only this time if you fall down, you'll have to backtrack to the previous pit to escape. So avoid dropping down at all costs and remain along the top.

Eventually, you will reach a wall and be forced to descend. Walk back to the left until you reach another wall beyond the spikes, and drop down to the level below. Walk to the right until you see a small pit before a final wall. Drop down this pit to access the boss arena.

Boss
The boss of the Toxic Zone is a robotic armor that floats in mid-air. It never touches down on the ground. It faces you and shoots an energy orb at your current position on the ground. Then it swoops down, advances towards you, and rises back up in the air on the other side, moving in a gigantic U motion. Then it turns around to face you and repeats the whole process again. In order to survive the battle, you must learn to dodge both the energy orb and the armor. The energy orb can be avoided by leaping straight up in the air as it approaches. As long as you are standing roughly half a screen apart, the orb should fly beneath your feet. The armor, it turns out, can be avoided simply by ducking. So you should attempt to leap into the air to avoid the orb, and squat when you land to avoid the armor. The only remaining question is when to attack. If you're fast enough on the attack button, you should actually be able to strike the armor twice before landing and squatting while the armor flies above you. Adjust your position so that you are half a screen apart again before turning around to repeat the process until the armor is defeated. It takes 16 strikes with the Laser Sword to win the battle.