I think you should also have the capability of reviewing the hint tabs again in the event you forget something over time. ... Like I have no idea how to sell a weapon/upgrade it's MK.
Artifacts, What they make, Where to find them, and what they're referring to
#1:
#2: The One Ring?
#3: Dragon Ball
#4: Energy Canister (Use with Cragman to make Tankman. Megaman/X Reference)
#5:
#6:
#7:
#8:
#9:
#10:
#11: Nuka Cola Cap (Depot Boy -> Warrior Brotherhood, Level 14, Fallout Reference)
#12: The wrench/can opener??(Solidman-> OldSnake, Level 10, Metal Gear Reference)
#13: ... ??
#14: Some kind of shield emblem.
#15: The Bat Sign (Batman)
#16: Fire Flower (Plumbers, maybe Princess Peach on # 14, Level 15, Mario Reference)
#17:
#18: Mortal Kombat
#19:
#20: VHS tape
#21:
Sorry, but this is as far as I got before SOMETHING happened with the game, and it glitched out, making me completely unable to train the cats anymore. it froze super hard then after a refresh it just messed itself up and killed my drive to keep going. Apologies to everyone.
I just reloaded the game, and all of the activate-able upgrades are constantly refreshing and constantly activating themselves.
https://www.dropbox.com/s/tcidgoo4swi4y2d/Screenshot%202014-08-19%2015.49.40.png
 "Transport Defender"){kind=icon}
 "Strikeforce Kitty 2"){kind=icon}
 "Clicker Heroes"){kind=icon}
 "Wake Up the Box 3"){kind=icon}
 "Take Something Literally"){kind=icon}