Here is the complete list of changes
Arquebus - Black outline
Bolus Sniper - Orange Line
Crusader Set - New helmet and sword
Mafia hat - Black outline for pickup and hat
Mafia Gun - 1 bullet less
Firecracker launcher - New sprite
Firework Launcher - New sprites
Toy Gun - New sprite
Pogo Stick - New sprite
Rail Gun - Pallet colors
Shield - More thickness and pallet colors
Building - Pallet Colors and outline
Golem Set - New pickup sprites, new sword sprite
Llama Gun - Black Outline and fewer bullets
Walrus Gun - Pallet Colors, more spread, less speed
Explosive Shotgun - Less rockets
Megaphone - Fixed Sprite
Hammer Gun - New Sprite
Spell Tome - Pallet colors
Mars and Moon rock - Pallet colors
Carboy - Temporal remove to make it a unique weapon
The Gun - Pallet Colors
Every Grenade - Less lag
Removed Flags
Removed Duck from the spawning pool

New Weapons:
Duck Hunter - A ballista, when hold will release a storm of heavy bolts
Air Striker - When picked rotates 90°, 3 rockets with gravity
Dusk Slayer - Blaster ammo, long range, great knockback. Right stick aim

There are some other guns that are still being fixed to work in the recent update, expect them soon