Crawky Forest is a large forest with three clearings connected by narrow paths. You start in the southern clearing, where you can find a Life Potion to the northwest and Remedia's Shield by following the path around to the southwest corner of the starting screen. The shield is expensive at 40,000 gold, but its power to block the projectiles of all overworld enemies is worth the cost.
There is a bug in the game in this area which complicates navigation somewhat. For whatever reason, the screen two north from the start has entirely the wrong layout. (It has the layout of the northeast corner of the area.) The effect is negligible coming from the south or west, but the map should connect the screens to the north and east to each other. This makes navigating this area a bit trickier later on. For now, make sure you buy the Bible here before moving on to the west.
The path leading north actually begins in the southwest corner of the area, but you'll find two caves via other western paths. The northern of these two contains a wise woman who is looking for another Ring, which you will find shortly. For now, head north along the western path.
You'll find a Bible guarded by tough White Stone Knights right away. Just east of there, you'll find an odd pond with a bridge going halfway across it. Fortunately, Rio is nearby to tell you what to do—stand on the end of the bridge and swing your sword several times. This will earn you the Ring the wise woman wanted earlier. You can bring it back to her, but her hint is not very useful.
Of far more immediate use are the White Rats you will find near a river in the area. They deal a lot of damage, but they drop 400 gold each and you can fight them safely from the river. (I find it's easiest to use the eastern bend for this purpose.) This is the only place you'll find White Rats, and is arguably the best place in the game to farm for gold. You will need gold shortly, since the Legendary Sword isn't far off and sells for a massive 50,000 gold.
Before heading east, head north to find a Life Potion guarded by White Porcupigs. There is nothing else of interest on the western side of Crawky Forest, so return to the pond where you found the Ring and follow the river east. Normally you could continue following the river all the way to Crawky's Cave, but due to the misplaced screen, the only way you can head from here is north.
At the far north end of the path, you'll find an area with two lakes, guarded by Death Lords and White Stone Knights. You can't even hurt the Death Lords right now, but if you take out two White Stone Knights, a cave will open. (If not enough White Stone Knights spawn, leave the screen and return to try again.) Within, you can buy the Legendary Sword for the hefty sum of 50,000 gold. It is well worth the cost, as the Legendary Sword deals double the damage of the Valley Sword, and can kill anything but a boss with one or two sustained sword strokes. Don't miss it!
With the Legendary Sword in hand, head south and east from the path to enter the northeast clearing of Crawky Forest. There is a Bible in the northeast corner, and you'll find Randar in the southeast corner. When you're ready, head south to find a Life Potion and Crawky's Cave. If you've collected everything so far, you should have 72,000 Maximum Gold and 17 Life Potions.
Crawky's Cave
This side-scrolling dungeon begins very heavy on combat, although none of the early enemies are a threat. The first Giant Snake doesn't even have some advanced attack—it just lazily tosses Red Snakes. Don't be lulled into a false sense of security.
At this point, things begin to pick up. After the Giant Snake, you'll find a bird figurine at the end of a hallway. Don't hit it! Doing so will lower a platform you need to jump on to progress forward. Shortly after, you'll need to make your way across some raised platforms without falling. You'll come across a floating bird figurine that you may assume is another trap, but this one you must hit to proceed. (The lower path here is a dead end.)
Soon enough you'll run into a nasty Giant Snake that fires eight Fire Spirits at a time, all of which home in on you. Attempting to avoid them is a good way to be ejected from the dungeon. Your best bet is to stand in front of the Giant Snake, where you can't be pushed back, and take the hits. The healing tokens will restore your health afterward.
At the three-way split immediately after, ignore the enemies and take the top route. You'll need to follow the bottom path instead at the next split. The bird figurine in the open area is another trap—hitting it will seal the path forward. The next figurine must be hit, but be careful not to fall between the paths to the lower level.
You'll soon come across another trivial Giant Snake. The fourth one of the dungeon, however, is anything but trivial. It fires waves of Fire Spirits, but what makes it dangerous is that there's nowhere safe to stand in striking distance. You'll have to charge back in after each hit. Fortunately, the obstacles behind you make it unlikely that you'll be ejected from the dungeon, but it is an intense fight nonetheless. A few sequences of breakable blocks are the last obstacle before Crawky.
Crawky is your toughest test yet. He will fly around the room quickly, firing off projectiles that bounce around for quite a while. At any given time you can expect to see 4–5 of them in play. It's hard to predict Crawky's vertical movement, so it's safer to stay low on the screen and try to attack him from the bottom. Even with a large number of Life Potions, you might need to use Mea to survive the assault.
When you are victorious, you will be rich and ready to move on to Haidee's Forest. (Truth be told, you can skip Crawky entirely for the time being, but you will likely need the money earned by defeating him.) You'll have to backtrack all the way to the northwest corner of the area to find the sixth Crystal, which is being sold for 30,000 gold.
Crystal in hand, follow the river east from Crawky's Cave to enter Haidee's Forest.