Flip cheese
You can do this either before starting the game proper, or after completing all other achievements. Don't do it halfway through, as it will wipe your save.
Download and use the following depot:
download_depot 3472810 3472811 8570721198019839785
This version of the game has a bug that immediately unlocks "Flip" upon buying Sign-flipping interns and prestiging. This saves several hours over the current version of the game.
Flipping in current version of the game
The sign flipping is unlocked when you run out of ingredients, resources, and money. The easiest way to do this is to, on a fresh save, buy ingredients for bullets, and then repeatedly and deliberately mess up the creation by clicking out of order until the sign appears. After this, getting the $100 and $1000 achievements is fairly trivial.
Note that sign flipping is much slower in the depot version, so using the current version is recommended for those two achievements.
Cheat codes
In the current version of the game the following cheat codes exist, and can be entered in the Settings menu:
humanzee - add 1 Prestige Point
showmethemoney - add $100,000,000
showmethebullets - add 100 ammo
showmethegrenades - add 100 grenades
showmetheguns - add 100 guns
showmethejeeps - add 100 jeeps
showmetheartillery - add 100 artillery
showmethetanks - add 100 tanks
showmethejets - add 100 jets
showmetheships - add 100 ships
The quickest way to progress the game is to repeatedly enter the cheat codes for grenades and guns until you get the 1,000,000 resource achievements, then repeatedly enter "showmetheships" and sell them in order to get billions of dollars, buy as many upgrades and automations as possible, then repeat the process into trillions of dollars.
At this point the only achievements you should have remaining are the ones that unlock along the way to getting 1 billion ammo. By spending trillions of dollars on ammo automation you can get this down to a 4-5 day idle. Make sure you've got any advantageous research upgrades, mines that are supplying enough resources for endless ammo production, and then spam as many ammo automation purchases as possible and wait.
