Here's a list of codes AMP Codes which still work. Shoutout to user AsherD123 who posted this list on the wiki:
fiveamp
gorgLife2
sassyRobot7
boley
riptide5
doggo
250rts
crazyforcoffee (great pickaxe, combine special with snowball and you get massive gains)
zzzzzz
wonster
jhsu
dan
balduranne
martiepie
havi
rockshield
awwman
superdoggo (beyond a great chest)
Every time i get meatloaf's dialogue of "It's my party and I'll cry if I want to." when he dies the timer just stops and doesn't go into the chest reward ._.
 "PickCrafter"){kind=icon}