I couldn't find a decent achievement guide on the internet so I decided to put one together.

For many achievements, it helps to play around with the modifiers(Burdens) to make things easier/harder to get certain achievements. Certain achievement related to weapons/items require you to get lucky and hopefully find it during your current playthrough. Every achievement is pretty much self explanatory.

There is only one achievement - Glutton for Punishment that requires you to turn on all Burdens and complete the game without portals.

Every other achievement can be achievement with or without modifiers.

• Secret Garden Unlock the portal to the Gardens.
  
  
• Raider of Tombs Unlock the portal to the Catacombs.
  
  
• Royal Welcome Unlock the portal to the Palace.
  
  
• Who's In Charge Around Here? Reach the final Boss Fight.
  
  
• Break the Curse Complete the game.
  
  
• The Hard Slog Complete the game without using the portals
  
  
• Glutton for Punishment Complete the game with all Divine Burdens turned on. No Portals. No Blessings
  - This is arguably the hardest and most time consuming achievement in the game. First you have to unlock all the burdens first.
  -I recommend playing as the soldier - They have good speed/health and a spear that does good starting damage
  - Play the game with all the easy modifiers first and collect all the gold/items you can. Make sure you use the 'insurance genie' and use insurance whenever you can. Hopefully you also find a few 'bank genies' as well and store some of your favourite items for the next run.
  -After you finish/die with the current run DO NOT SELECT RESTART GAME. Instead go to the menu and select new game. Turn off all the easy modifiers and turn on all the Burdens. Make sure you select the soldier class and your money/items will be transferred over to your game. It will still be very very challenging but at least you will have some advantage starting out.

Under New Game you can select the burdens you want to make the game harder. Just highlight the Burden and the game will tell you what you have to do to unlock it. After you unlock it, you can then select it for any future play through.

Most of these will come naturally when playing the game so don't worry too much about these.

• I Can Take It Unlock the Deadly Divine Burden.
  
  
• Night Owl Unlock the Eclipse Divine Burden.
  
  
• The Bigger They Are ... Unlock the Stout Divine Burden.
  
  
• They Keep Coming! Unlock the Rebirth Divine Burden.
  
  
• Try To Keep Up Unlock the Breakneck Divine Burden
  
  
• Watch Your Step! Unlock the Excessive Divine Burden.
  
  
• Who Needs Genies? Unlock the Unhelpful Divine Burden.
  
  
• Borrowed Time Unlock the Deadline Divine Burden.

• First blood You need to die. Just once. It'll be painless.
  
  
• Slide Tackled Trip 20 enemies by sliding into them.
  -Just run and duck and you will slide into an enemy
  
  
• Return Serve Disable Etol the Hurler by reflecting its projectile.
  -These are the genies who throw fireballs at you. Simply wait for it to throw a fireball and hit it with your whip.
  
  
• A Grave Mistake Die whilst at full health but poisoned.
  -This will require some luck. Multiple ways of getting poisoned; Drinking a bottle of venom, opening a trapped chest or hitting a vase with poison.
  
  
• Weep No More Kill a Silent Effigy.
  -These enemies appear in the third area; the catacombs(levels 7-9). They follow you when you turn your back to them. Easiest way to kill them is to find an exploding urn/vase and throw it at them.
  
  
• You're wide open! Use the alternative whip fire to pull away the shields of 10 enemies.
  These enemies appear in the third area; the catacombs (levels 7-9). They have large shields on them, simply use your alternative whip fire on the shields to expose them.
  
  
• Pop Goes the Weasel Kill three or more enemies with one Cask of Volatility.
  -This can be done in the first area of the game.
  
  
• Can't Hide From Me Find 25 secret rooms.
  - Look at the other steam guide to know what to look for. This can be done over multiple playthroughs. Easiest done in the first area (first 3 levels).
  
  
• Clean Sweep Hit three different enemies with one sword swing.
  
  
• Playing With Your Food Trip, Stun and Disarm the same enemy.
  -Use your whip on the arm,legs and face of one enemy.
  
  
• Foul Move Distract three enemies using one Puzzling Foul.
  -These are the blue chickens that appear in the first 3 levels. Pick one up and throw
  It in a large crowd.

• A Well Travelled Fool - Complete 15 runs as The Fool or Traveler.
  
  -For these types of achievements, you can just start a game, run to the first trap and die. Rinse and repeat.
  
  
• Collector - Equip 9 different swords as The Fool or Traveler.
  -This will require some luck. Just set all modifiers to easy and play through the game. You do not need all of them in one play through, you can get this over a series of tries. Just prioritize buying new weapons whenever you are given a chance.
  
  
  
• Mastered the Basics - Complete the game as The Fool or Traveler.
  
  
• Hammer Time - Trip 30 enemies using the Hammer of Quaking.
  -Requires you to find and buy the hammer and use it on enemies.
  

• For Honor! And Gold! (Mostly Gold) - Unlock the Soldier.
  
  
• Battle Hardened Veteran - Complete 15 runs as The Soldier.
  
  
• Total Recall - Recall the spear 20 times.
  - When you throw the spear, just recall it back by pressing the same button.
  
  
• Shish Kebab - Kill three enemies with one thrown spear.
  - Use the Burden that adds more enemies
  
  
• Cruel and Unusual - Kill 10 enemies by pulling out the Pole of Mangling.
  -First you have to find and buy this particular spear. Throw it at an enemy and then use the whips' secondary function to pull out the spear from the enemy and hopefully it will kill them.
  PLEASE NOTE: If you throw the spear at an enemy and then recall it, nothing will happen, you must use the whips secondary function.
  
  
  
• Soldier of Fortune - Complete the game as The Soldier.

• A Thief in the Night - Unlock the Brigand.
  
  
• Accomplished Thief - Complete 15 runs as The Brigand.
  
  
• Successful Heist - Complete the game as The Brigand.
  
  
• Alright Everybody, Chill! - Freeze 15 enemies using the Skewer of Chilling.
  -First you have to find and buy this weapon and then keep using it.
  
  
• On the Rebound - Kill two enemies with one thrown dagger using the Edge of Ricochet
  -First you have to find and buy this item, and hopefully when two enemies are near each, throw a dagger and hopefully it kills two enemies. Works best in the first few levels when enemies are weaker.
  
  
• Porcupine - Hit the same enemy with all the daggers in a full hand 20 times.
  - Using the burden that gives enemies more health helps hear. Just keep throwing daggers at the same enemy until they die.
  

• Up for a Brawl - Unlock the Hellion
  
  
• Heavyweight Boxer - Complete 15 runs as the Hellion
  
  
• Smash and Grab - Complete the game as the Hellion
  
  
• Punch Line - Kill 15 enemies by punching them into a trap
  -Use the burdens more enemies and traps to make this easier. Stand in front of a trap and punch enemies into it. The hardest part about this achievement is getting the enemies in the right place, using your whips alternative function helps here.
  
  
• Disarming Blow - Disarm 10 enemies with the Cuffs of Disarming
  - First you have to find and buy the item and then use it.
  
  
• Knock Out - Kill 20 enemies with a fully charged punch.
  

• Hahahahahaha! - Unlock the Revenant
  
  
• Dun-dun-DUN! - Complete 15 runs as the Revenant
  
  
• I'm free! - Complete the game as the Revenant
  
  
• (Dry Sucking Noises) - Heal 10 hearts using the Missile of the Leech
  
  
• Heh heh heh! - Kill three enemies at once with a single Projectile of Ignition
  
  
• Kaboom! - Kill 15 enemies using the Torpedo of Blasting proximity mine