First things first: this is, unfortunately, not a guide on how to complete the achievements. I'm not even remotely qualified to talk strategy as of yet, there might be another guide out there that can help you with that if that's what you need!

What I can offer however, is an easier way to look at all the achievements. I got overwhelmed by the amount of them early on and it caused me to just avoid playing this game altogether, for almost 4 years! Sorting through them helped me overcome that and I'm having so much fun with this game now, so I'd like to provide what I can in hopes it will help someone.

The good news for anyone who is overwhelmed? Really, there's only 6 types of achievements in the game, which are used over and over again with different details.

Where applicable, I believe these can be earned in Challenge Coin runs as well. These are very straightforward, and I don't think new achievements will be added to this category anymore.

• Introduction Mode
  
• Daily Draft
  
• Normal Difficulty
  
• Hard Difficulty
  
• Impossible Difficulty
  
• Impossible + Instability 5
  
• Impossible + Instability 10
  
• Impossible + Instability 20
  
• Impossible + Instability 30
  
• Impossible + Instability 40
  
• Impossible + Instability 50

Every time you beat a run with a character, you'll be able to choose 1 card to master, of which there are 10 available. This essentially means you just have to win 10 runs with each given class. Naturally, new achievements will only pop up here when a new class is brought into the game.

• All 10 Hidden cards
  
• All 10 Tempest cards
  
• All 10 Enlightened cards
  
• All 10 Daughter of the Void cards

This can be done on any difficulty, so even if you only dare to engage with Normal mode you can still get these. I believe these are all Floor Guardians, of which there are 2 every run, but I could be mistaken. New achievements will be added whenever a new boss of this type arrives.

• Birth Pit
  
• Black Carriage
  
• Bloodhive
  
• Cursed Swine
  
• Dreamcatchers
  
• Priest
  
• Skeleton King
  
• Swamp Mistress

These are all the other boss enemies in the game and will have to be killed without taking any damage on Hard Difficulty or higher. I think this includes Elites, as well as the Void and its guardians, so when a new one is added a new achievement will be added here as well.

• Beast of Malice
  
• Bruce
  
• Corellion Solspear
  
• Death Knight
  
• Dolus
  
• Hag
  
• Incubus Lord
  
• Mare
  
• Obsidian Golem
  
• Phobos
  
• Puppetmaster
  
• Queen of Ages
  
• Skeleton Mage
  
• Spidernest
  
• Star Council
  
• Void

The special Void kills, new achievements could potentially pop up here when new playthings are added. This currently includes killing the Void with the seven Sins cards in your deck, as well as killing the Void after taking a relic for Arkaos and doing so once with each relic.

• In deck: Envy Sin
  
• In deck: Gluttony Sin
  
• In deck: Greed Sin
  
• In deck: Lust Sin
  
• In deck: Pride Sin
  
• In deck: Sloth Sin
  
• In deck: Wrath Sin
  
• Once with each Arkaos Elemental Bead relic

This is by far the largest category of achievements; as of writing this takes up 189 out of 237 achievements and will be by far the most time-consuming. This is also the category that gets added to the most frequently, new Challenge Coins get added pretty often!

There are three types of Challenge Coins:

• Empowered challenges, despite being called challenges, are actually easier than a vanilla run and will give you extra benefits. Lots of fun to be had here!
  
• Twisted seems to push your build in a certain direction by providing a challenge to overcome, which might benefit you if done well.
  
• Grim is just here to pose a problem.

As for the actual achievements, there are 4 attached to every challenge. If you earn the Medal of a higher difficulty, the lower ones are automatically unlocked alongside it.

• Earn the Normal Difficulty Medal for every Challenge Coin
  
• Earn the Hard Difficulty Medal for every Challenge Coin
  
• Earn the Impossible Difficulty Medal for every Challenge Coin
  
• Earn the Impossible + 30 Instability Difficulty Medal for every Challenge Coin
  
• BONUS: Earn 50 Medals in total

And that's it! In the interest of making things less overwhelming I've kept it short, but feel free to let me know if there are more details you want covered in this guide.

Happy gaming!