For Rusty Gun players, this is an 100% achievements guide for Rusty gun and includes screenshots for hidden posters in game as well, let’s check it out.
Intro
Achievement guide mostly created for showing locations of Hidden Posters as those are not that easy to find.
At the bottom

This can be done right away in Level 1, just go to the left when you start.
To the eyeballs

Like description says, 100 bottles of beer (might be necessary to do it in one session)
As fragile as crystal

In level 15 after defeating the boss, shoot him a bunch of times
Nautilus

In level 16 hold left and keep on shooting the guy until the submarine sinks.
Fluffy and oblique

Defeat boss in level 3
A wonderful miracle

Defeat boss in level 7
Uninvited dinner

Defeat boss in level 12
Cold blooded

Defeat boss in level 15
Tight Bandana

Defeat boss in level 17
Secret number 1

In level 3, after 1st checkpoint, near long ladder where 2 shooting heads are attached to thick wall. Jump from top and hold right

Secret number 2

In level 5, after a checkpoint, to the right side of the 2nd enemy with shield (before enemy with a gun)

Secret number 3

In level 7 right after 1st checkpoint, behind shooting head and below spikes

Secret number 4

In level 9 pretty close from the start, after pressing first button keep on going right until you find a wall with a button above it

Secret number 5

In level 11 above the room with 2 doors, after you access the left door (before 3rd door)

Secret number 6

In level 13 right after place where you have to bounce up with “snow”, to the left of the ladder

Secret number 7

In level 17 from the start going to the right and up, hidden behind 2 beers (near first button)

Secret number 8

In level 17, after passing first doors going to the left and up, next to another button

Collector

You will get it when getting last poster
That’s all we are sharing today in Rusty Gun – 100% Achievements Guide, if you have anything to add, please feel free to leave a comment below, and we’ll see you soon.
Credit to Mat2PL