Necesse doesn't communicate progression too well to players who don't prioritize questing. This can cause a lot of frustration for new players, who often find themselves settling in a biome which, upon going underground, doesn't let them do any exploring! They then have to go back to biomes other than their settlement just to start playing the game.

Furthermore, upon being able to access the undergrounds of all the biomes, they may have rushed beyond the quests intended. The existence of more progression is only hinted at by a few accessible crafting recipes, then.

If you've found yourself in this situation, this guide is for you.

First, the rundown. If you want to figure out most things on your own, this should give you enough info without going too in-depth.

• Progression is mostly gated by pickaxe strength, but most pickaxe upgrades are simply faster, not a progression upgrade.
  
• Much like the early-to-midgame progression, the mid-to-lategame progression is gated by defeating a boss. This boss, however, isn't one you can summon yourself.
  
• Lategame progression mirrors early-midgame progression.

Moving on from here, we'll go further in depth...

In Progression:

• Forest Caves, Snow Caves

Earlygame progression is, thankfully, simple, although it defies many people's desire to immediately go exploring. Instead, the game seems to expect you to stick around in the starting biome and to complete the Elder's quests... Annoying, since to get quests at all you have to start your settlement.

You don't actually need to do anything, theoretically, before fighting the boss that lets you into midgame. If you're dedicated, you could beat it exactly as you come. This is not recommended, as the boss can only be fought during the night and you are very squishy without armor.

To find the boss, defeat enemies in the Forest biome/caves until they drop its summoning item. Defeating the boss rewards you with Demonite Bars, which when formed into a pickaxe officially allow you to progress into midgame.

Fun fact: Midgame ores can actually be mined early using Iron Bombs. Their explosions can destroy anything in the regular Caves. You still need Demonite for the crafting station to actually use these ores, however.

In Progression:

• Forest Caves, Snow Caves
  
• Desert Caves, Swamp Caves

Moving into the midgame, you can officially now actually settle anywhere and be able to access its caves, hoorah! Your Demonite Pickaxe is actually very powerful: Although you can get stronger pickaxes, it's all you need (plus another boss fight) to progress into lategame.

Midgame opens up a lot of opportunity, so you'll probably want to stay there a while to build up your settlement. Once you enter it, your settlement will start getting raided. For each new unique boss you defeat, the raiders will get an upgrade in both numbers and equipment. However, defeating the midgame bosses is entirely optional, except for the one that gives you lategame access.

Unlike the earlygame boss, you have to seek the boss that gates lategame out yourself. There is no summon, rather a special biome type you'll either stumble upon while exploring or find a map for. This boss is significantly harder, even with end-midgame gear. Melee is not recommended unless your weapon also has a ranged component.

Upon defeat, the boss drops a ladder to the deep caves, allowing access to lategame.

In Progression:

• Forest Caves, Snow Caves
  
• Desert Caves, Swamp Caves
  
• Deep Forest Caves, Deep Snow Caves
  
• Deep Desert Caves, Deep Swamp Caves

Technically, lategame is split similarly to early/midgame, although to a bit of a smaller degree. You can't plop down your deep caves ladder just anywhere and start going, because while your Demonite Pickaxe will get you into lategame, it won't get you very far.

You'll have to go back to the Forest biome and enter the Deep Forest Caves first. Your target: Tungsten. Much like Demonite, once you have Tungsten you're able to do everything, though upgrades are still available. You'll need enough for a pickaxe and the next tier of crafting station, though if you want to just get enough for the pickaxe here, it is available in all Deep Caves biomes.

From there, you're home free! Everything in the game should be available to you, at least in this update.

Unfun fact: The Iron Bombs do not explode deep caves tiles, so sadly you are required specifically to go to the Deep Forest Caves to get your Tungsten.

Earlygame to Midgame:

• Forest & Snow Caves Only
  
• Fight Forest's Summonable Boss
  
• Obtain Demonite Pickaxe

Midgame to Lategame:

• All Regular Caves
  
• Fight Unique Location Boss

Lategame to Endgame:

• All Regular Caves, Forest Deep Cave
  
• Obtain Tungsten Pickaxe

If you see any mistakes, let me know! This guide was compiled out of my own frustration, and only lightly fact-checked. I hope it helps others with the same problems.

I've made some mote progression in my own game, discovering that the content in this guide near the end is wrong! Don't have the energy to fix it completely rn, but:
- Lategame progression requires going from area-to-area, a tungsten pickaxe won't get you as far as the demonic one did.
- There's at least 1 more workstation type, possibly meaning another progression section to write.