Achievements count - 19
Achievements complexity - 0/10
Time to 100% - 1 min

Buy this DLC, start a new game, click on the button under the character portrait.

https://store.steampowered.com/app/1359780/No_Turning_Back__Unlock_All_Classes/

Open the game and start your run, then die. It will create a savegame file here: C:\Users\{your user}\AppData\Local\NoTurningBack_Alpha12\savedata.ini

Close the game, open savedata hile with any text editor and replace its content with this text:

[stats]
enemiesbledout="1000.000000"
enemiesburnt="2.000000"
level="10.000000"
coinscollected="1.000000"
deaths="5.000000"
kills="1000.000000"
cultistkills="1014.000000"
bloodspilt="1036.640000"
soulscollected="10000.000000"
batkills="11.000000"
crystals2="1.000000"
[options]
tips="1.000000"
music="0.000000"
sound="0.000000"
[headquarters]
ordername=""
roomscleared="12.000000"

Launch the game, open class tab and enjoy your achievements.