I think this is one of the easiest hard badges in my opinion. Just because you get so much money before you fight the last boss. I personally bought the minigun like four waves before the last boss. Well, to me it was easy :P
uhh, I think there is a bug where I can't select the level I want to do again after I beat the game. I went to the 59 wave and I was forced to do 60. I couldn't go down to 58 for example.
an easy way to get the 100k achievement is to just get 14k when the game gives it to you and build defences and purchase upgrades for them. Lather, rinse, repeat.
39... first add all the blocks to the top, then put the giant pillar at the bottom right of the screen where the smiley is then add the balance beam on the pillar which will stabilize the blocks falling to the right and add the triangle. That's how I did it.
 "Bible Fight"){kind=icon}
 "Don't Look Back"){kind=icon}
 "Bunny Invasion 2"){kind=icon}
 "You Have To Burn The Rope"){kind=icon}
 "filler"){kind=icon}
 "Jumpcat"){kind=icon}
 "Onslaught2"){kind=icon}
 "Turkey Fling"){kind=icon}
 "6 Differences"){kind=icon}
 "Papa's Pizzeria"){kind=icon}
 "Super Stacker 2"){kind=icon}
 "Perfect Balance"){kind=icon}