Part One: The Great Escape
The Dungeon
Erik's Cell
In true Shadowgate sequel fashion, we start off locked in a dungeon cell. Open up your inventory to find that the guards neglected to fully search you. Select the Match in your pocket and use it on the nearby pile of hay. Erik will run to the left and a Guard will barge into the room to extinguish the fire. If you just hang out, or move to slowly, the Guard will run up and kill you in a single stab. To prevent this, you need to act prematurely. Once Erik starts moving to the left after lighting the fire, immediately start pressing right. As soon as Erik returns to your control, he'll start moving toward the guard as a result. You should be able to get behind him and be within striking distance before he turns around and notices you. Punch him once to dispatch him.
Once the Guard is downed, he'll drop a couple items. Pick up the Bucket and the Keys from the floor. Use the Keys on the door to unlock it, then move out of the room.
Cell Block 1
You'll be greeted with a scene of your dead dad killing a couple guards. His ghost will speak with you for a bit before vanishing from whence he came. Move left until you leave the room.
Back Hall
The door on the right contains some optional stuff that we're going to skip for the purposes of this walkthrough. Use the Keys to unlock the door on the left. Move on through to the next room.
Commissary
Save the game. Charge the Guard and punch away once you're right on top of him. Your goal here is to get in 6 punches before he can stab you 3 times. He'll often pause to laugh at you, so you'll have chances to wail away, but it's still oddly easy to die here. Once your enemy is defeated, pick up the Pepper shaker from the table. Make your way back to Cell Block 1.
Cell Block 1
Wander your way to the right. The other cell in here (besides the one you started in) does not contain anything useful. Unless you want to poke a dead body. Odd proclivities aside, just exit to the right.
Cell Block 2
Save the game. You'll be confronted by two Guards as soon as you enter the room. They each have the same stats as their compatriot in the Commissary. How can you defeat both before getting hit three times, you ask? Simple. Charge one of the Guards and punch away until he's defeated. Once he's down, turn left and leave the room back to Cell Block 1. Entering a new room resets your health to max, so now you can safely head back into Cell Block 2 and take out the remaining Guard.
Now that the room has been cleared of enemies, we can proceed. There are two doors here: one of them contains an optional event, and the other is blocked. We're just going to skip over the option stuff again, so make your way to the right edge of the room and go down the stairs.
Stairs
Nothing to do here, so just exit to the left.
Cell Block 3
Both the cells in here are technically optional, but we're going to enter the one of the left anyway. Use the Keys on the left door and then head inside.
Cell 2
There's an old man in here with a paddle ball. Erik will inform him that he's free to go, and he'll give an appropriate triumphant cheer before escaping. Take his abandoned Paddle Ball and then leave the room.
Cell Block 3
Exit to the left.
Cell Block 4
There's one door in here, but it just leads to an empty cell, so it's best to just ignore it. Exit to the left.
Minotaur Cell
There's a fearsome Minotaur chained to the wall. Looks more like a buff Deer Lady, but I guess we're sticking with minotaur. Save the game. Time to go beat up a mythical creature! You know the drill by now, charge in close and punch away. You can take 8 hits from those fearsome claws, and he'll go down after 6 furious punches.
Once the Minotaur has been felled, operate the trapdoor it was standing on with the Icon of Touch. Erik will tug on it, but it looks like he was unsuccessful in opening it. Step away from it and it will fall open. Walk around to the top and then climb down the ladder. Note: if you stand on the trapdoor after Erik opens it, he'll fall down the pit when it opens up. Also, don't approach the open trap door from the side.
The Caves
Entrance
Erik will climb down the ladder all on his own. Enjoy.
Cavern A
Pick up the Leather Bag from the ground, then exit to the left.
Cavern B
Make your way to the left. As you near the edge of the room, you should be able to spot a small piece of Quartz on the ground. This is an extremely important item, so make sure you pick it up. Exit to the left.
Crystal Cavern
Save the game. Carefully make your way to the left. After you hit a certain point, a Cave Dweller will charge in from the right and bite off your leg. Obviously, it would be preferable if it did not do that, so turn to face it as soon as you see it appear. You can just punch it normally when it raises up to bite, but it's far easier to turn, crouch, and punch low. If you're quick enough, you can deliver a killer boop to the snoot before it gets close enough for the kill. If you weren't fast enough...well, that's what the save file was for. Once you survive the encounter, continue left into the next room.
Steam Cavern
There's a pipe belching forth steam. Use the Leather Bag on it to create a makeshift hot air balloon and float upwards.
Elevator
Erik alights upon a ledge. There's a wooden elevator here that you can take back down if you want to. No reason to do this, unless you missed the Quartz, so just exit to the right.
Mulnear Cavern
This room is patrolled by a fearsome Mulnear. I don't think you can kill it with your normal punching tactics (and it you can, it takes a ridiculous amount of punches to the point where it isn't worth it), but it's pretty easy to slay nonetheless. Just use the Pepper on the Mulnear and it will sneeze itself to death. Pick up the Gem on the ground and exit to the right.
Mushroom Cavern
Head to the right until you see a giant blue mushroom. It will eat you if you get too close, so be sure to keep your distance. Operate the pipe above it with the Icon of Touch (might need to search around for the right spot) and Erik will jump up and redirect the pipe to blast the mushroom with steam. Walk past the husk and exit to the right.
Cavern C
Nothing to see here except for some harmless bats, so exit to the right.
Lava Cavern
Use the Bucket to plug up the source of the lava flow, then exit to the right.
Troll Cavern
Head to the right until you encounter a Troll. He won't let you pass unless you pay him. Right now you are holding three things that he'll accept as payment: the Gem, the Quartz, and the Paddle Ball. None of these are great options, however. Giving him the Gem will block us from getting some money later, the Quartz will render the game unwinnable, and the Paddle Ball will rob us of one of the endings (my favorite one, in fact). The best option, then, is to walk up to the Troll and punch him once. He'll collapse in tears, allowing you to walk past him. Exit to the right to finalize your escape.