Wonder Boy in Monster Land/Round 6

Part A

 * 1) You begin on the left side of the pyramid.  The entire floor of this section is composed of spikes which you must do your best to avoid falling on.  Unless you happened to splurge on shoes early in the game, you will have to take particular paths across the platforms as they become available.
 * 2) Starting out, you will ignore the highest block, and jump from the middle block to the low block in order to reach the floating platform.  Don't jump on the floating platform until it is rising, then leap to the next section.
 * 3) When you jump on the next small block, a spring will boost you to the top block which you can use to reach the next floating platform.  If you drop down to the lower block, you will have to drop to the spikes below and reach the ladder as quickly as possible
 * 4) A Death will be waiting for you between the second and third sections.  It should be much easier to defeat with an enhanced sword.  Take it out the same way you did in Round 1 before continuing on to the next section.
 * 5) The third section seems like the first section, but as soon as you land on the low block, it begins to sink.  You can tell sinking blocks from regular blocks because they do not have a drop shadow in the background (or they are differently colored in the SMS version.)  Carefully hop off this block as soon as you land so you don't sink too far to reach the next platform.
 * 6) Another Death will greet you here.  Remove it and prepare for the final section.  It has multiple sinking platforms.  While you should try to move across quickly, you don't actually have to make the final jump in one attempt.  If you continue to jump on the final sinking platform rapidly enough, the platform will actually rise back up to a height that you can easily leap from to the last ledge.
 * 7) If you do happen to have the best boots, or perhaps Winged Boots, you can jump back to the left to the section of the map labeled "!", where you can push up to discover a secret door.  Behind it, you will find a shop which has secret weapons, but it will also sell you Medicine for 100 gold if you ran out.

Part B

 * 1) Where you begin in this section depends on where you left the previous section.  If you made it to the top ledge in part A, you will begin in the highest hallway on the left of part B.  If you exited through the spiked floor, you will begin near the middle instead.
 * 2) If you arrived in the highest hallway, you will have access to the hospital behind door A, but you must reach it first.  Kill the three snakes and jump over the gap.  The floor of the dug out area between the two pillars is loaded with springs, so it is impossible to stand still in there.  There are two skeletons in the arcade and PC Engine version, or a cobra in the SMS version.  Door A is guarded by a cobra in the arcade/PCE version, and a spitting plant in the SMS version.
 * 3) The section below door A has a curious property.  The floor is lined with spikes, so this trick is only practical if you happen to have Winged Boots on at the time.  Every time you cross beneath door A, a coin will appear.  Collecting the coin without getting hurt is extremely difficult without the Winged Boots.
 * 4) Back to the left side of the second level, where you would have arrived if you exited from the spikes in part A, you will notice something between the two pillars.  At the location labeled "!" on the map, you can push up to discover an armor shop.  Unless you can afford to purchase the Legendary Armor for 540 gold, don't buy anything.
 * 5) Removing the snakes and the blue rat (which takes several more hits to defeat than a red rat) from your path, drop down the gap between the ledges.  When you land, head left and jump across the next gap to reach door B.  Unlike other bars, it is actually fairly important to buy a drink here.  Buy the full priced drink for 15 gold, and you are likely to receive a hint about Sphinx.  Do this twice if you don't get the hint the first time, or need more hearts.
 * 6) Once you have the hint about the Sphinx, drop down the gap to the right of door B, and proceed right.  You will encounter a Spitting Plant, perhaps for the first time.  Spitting Plants are difficult to approach, but once you get near them, you can frequently stab them until they are defeated.
 * 7) Beyond the plant are two blue skeletons.  (The SMS version will have two red rats instead.)  Blue skeletons are tougher than red ones, but the method to defeat them is the same.  Once you have removed them, climb up the platforms to door C, and enter when you are ready to do battle with Sphinx.

Boss
The Sphinx is an incredibly difficult boss to defeat, but if you're smart (or lucky) you may not have to fight him at all. It all depends on whether you received a hint about him at the bar behind door B (or you make a lucky guess.) Before the fight begins, Sphinx will ask you a question about himself, and give you three choices for the answer. You will either know the answer from the hint you were given, or you will simply have to guess. If you answer correctly, Sphinx will honor his deal, and allow you to pass, providing you with eight coins in the process. If you get the question wrong, you will have to engage in a particularly difficult battle.

Sphinx fights by standing in one place and sending lightning bolts in your direction. The bolts can be blocked with a shield, but if you're too close to Sphinx, they are more likely to hit you in the head, making them difficult to block. When you approach Sphinx, he begins to flash and teleport to another portion of the room. Where he arrives is somewhat random, so it may be close to you, or far away. Either way, you must rush over and stab him (hitting him the foot is acceptable, but it's easier to hit him off the ground) before he begins to flash again. Sphinx has a lot of hit points, and this becomes a very tedious battle, one that is difficult to survive even if you have medicine. It is far better to get the question right than to have to deal with Sphinx.

Arcade/PC Engine

 * From the highest hallway in part B, jump across the first gap and stand in the middle of the platform you land on to make three money bags appear.