Gun Ugly

First achievement unlocks on Startup or when you go to start a New Game

For the next 5 achievements, which are (1.Power Gamer, 2.Tactical Chaos Operations3.Bad Exit, 4.The Ceaseless Finality of Change, 5.Viewer of Horrors)
New Game > Nightmare > ESC on keyboard > Skip levels until the end of the game

For High Roller you need to get keys which you can do by beating levels or replaying the same level x5 times.
This achievement is RNG dependant so if you want you can backup your save at Appdata/LocalLow/PaulDaubly/GunUgly
before you open any of the lootboxes so if you don't get it you can just reload the save. I got lucky and after 5 or so keys the achievement unlocked.
So i never had to backup my save.

And after all of this and around 10 to 25 minutes ,you should have your 100% for Gun Ugly !