6Braves is a free classic-style magic tower game. In the game there are 6 different kinds of characters, 5 of them you need to unlock them via diamond. The diamond will be awarded for clearing the game. Diamonds can also be used for unlocking more equip slots and yellow/ blue keys, which will be very helpful for beating high difficulty games.
You will need to unlock all playable characters for 100% achievements.
Note: this game does not have steam cloud, so you need to take good care of your save files (located at C:\Program Files (x86)\Steam\steamapps\common\6Braves\save).

The diamond system in game works as follows:
Diamond income:
1. You will be given 100 when you open the game.
2. Each character clear Easy - Hard game will give you 100 - 300 gems, Level 99 Extreme will give 150 more or so. (450 in total)
3. Redeem gift code from the author.
4. Clear the new added night tower will give gems as well (not tested).
(Note: you can get one character code from http://zeros.group/bili/ as of today)
Diamond shop:
1. Each equipment slot costs 300 diamonds, it will decrease game difficulty significantly.
2. Each character costs 600 diamonds.

If you are stuck, please reference guides on bilibili and youtube.

These achievements should be straight forward

• Assassin
  Unlocked Character - Assassin
  
• Magician
  Unlocked character - Wizard
  
• Summoner
  Unlocked Character - Summoner
  
• Undead Warlock
  Unlocked Character - Undead Warlock
  
• Knight
  Unlocked Character - Knight

Note: do not skip after defeating the demon king

• The adventure sets sail
  Adventure into the Magic Tower
  
• The first sword
  Obtained the first sword in the game
  
• Don't stop!
  Defeat the first boss
  
• It's too late
  Sensed the ambush, but had no choice but to get hit
  
• Enemy of the Vampire
  Defeat the vampire
  
• Dragon Slayer
  Defeat the Dragon
  
• A dilemma
  Defeat the Demon Knight
  
• Excellent Decryptor
  Solve the 45th floor puzzle
  
• Fight the Demon King and win
  Any character has successfully challenged the Demon King
  
• Brave Man's Dream
  A long dream, still moving after waking up

• Ordinary brave man
  Pass medium (or higher) difficulty
  
• Awesome Brave
  Pass Hard (or above) difficulty
  
• The brave man who saved the world
  Pass Hard 50 (or higher) difficulty
  
• The brave man who surpasses the gods
  Level 99 (or higher) on Extreme difficulty

• Chamber Seeker
  Found the secret room
  
• Something else
  Enter the dark room on the 46th floor
  
• First hidden area
  Found the first hidden area
  
• Puzzle new to me
  Solved the first puzzle
  Secret Room location: Floor 6 (upper left corner), Floor 11 (upper left corner), Floor 46 (bottom right corner), after you enter each of them and solve the puzzle in floor 6 secret room you should have these achievements.

• Fight magic with magic
  Enter the Magic Tower with a wizard character
  
• Melee Mage
  Defeat the first boss with a wizard
  
• The Birth of a New Demon King
  The birth of a demon king is never an accident
  (clear the game and do not skip at last)

• The road to assassination
  Use Assassin character to enter Magic Tower
  
• Tomb Raider
  No way, someone even stole the tombstone?
  (Floor 41, grave, choose second option)
  
• The Demon King's private money
  Enter the 53rd floor
  (Use special ability 2 to pass demon king on floor 52)
  
• Assassin's Trial
  It's a trial~
  (clear the game and do not skip at last)

• Summoning the Law
  Use a summoner character to enter the Magic Tower
  
• Colorful
  Gain the ability to summon all summons
  (Unlock for getting the first 5 skills for summoner)
  
• My Friend the Demon King
  Friendship is especially precious under the extreme
  (clear the game and do not skip at last)

• Smash the light with darkness
  Defeat the Mage of Light
  
• I'm not an evil Slime!
  Do you think you can kill a slime that's so cute?
  (Second floor, kill 2 bats to go upstairs instead of killing the green slime)
  
• Interest first
  Killed the Green Slime that let go. If not killing Green Slimes is for the reward, then killing Green Slimes is also for the reward
  (Followed by above, after getting 'I'm not an evil Slime!', kill the green slime.)
  
• The destruction of the world
  The destruction of the world by numerical explosion
  (After defeat demon king, choose first option)
  
• Demon King Savior
  Saved the Demon King, but is the Demon King still the original Demon King?
  (After defeat demon king, choose second option)

• Detect the trap
  Bypassed the Demon King's trap
  (Floor 18, don't use the middle path to go upstair.)
  
• Newbie Operation
  To open the door you need to get the key, understand?
  (Floor 0, try to open the yellow door without first getting the key)
  
• Excellent Decryptor
  Solve the 45th floor puzzle
  (Use summoner or assassin, at floor 45, Open the yellow door to make it appears as '5' )
  
• The Cursed One
  Cursed
  (Use one of the black stones in game, e.c the one in floor 13 and 14)