Friday the 13th: Killer Puzzle

This is a massive grind. You have to get 1 copy of all 120 weapons at once (Basically this will be the last thing you do in the game). Biggest issue is that there are 30 "Recipe" weapons that can only be obtained from trading specific items (or by purchasing for real money ($$) the "loot boxes"). There are also 11 weapons (I think) that are "free" from the DLC's, but it does require purchasing those DLC's (but as I was unlocking this, I did get a couple of these from the 'Daily Death Streak' - though it might have been because I already had it from buying the DLC's). Biggest hint is to not just trade willy-nilly, but to focus on trading for the recipe weapons. Once you trade for the weapon, you have a random change of that weapon showing up in the Daily Death prizes. For the quickest strategy to farm these, is to repeat the 'Daily Death Streak' as quickly as you can (since this will get you 5 weapons after 13 days plus about 3 more while completing the levels). To do this quickly open this spoiler:

So far it appears that the Loot/trading system has been upgraded as of Game Version 1.7.1 where it seems to give you random non-recipe weapons that you don't have (instead of duplicates) when you trade. Once you have all the non-recipe weapons you will start getting random duplicates (again, non-recipe). Earning weapons from leveling up seems to be much more random and may give you a duplicate. More on the details of this (and where I got most of my information on it) can be found from the Steam gamer Bootch here: https://steamcommunity.com/app/795100/discussions/0/16937958...
I have personally found that trading 3 golden weapons can randomly land you a recipe weapon but I've also gotten a regular gold weapon with the same trade.

There is a great guide from Bootch for all the weapons and their recipes here: https://steamcommunity.com/sharedfiles/filedetails/?id=13652...
but to save you some hunting, Here are the recipe weapons: Unlocking this achievement will also guarantee that these achievements will unlock along the way: well: