Sprites:
Muzzleflashes - Ripped from Duke Nukem Forever (2001) by LFW
Arms - TG5
Fist, chainsaw, pistol, super shotgun, chaingun - TG5
Shotgun - TG5, with a barrel from Skelegant's OHM shotgun
Rocket launcher - Original rip of the Helldivers 2 EAT-17 rocket launcher by Poteto Bloke, edited by me + some gubbins from Tesefy
Plasma rifle, BFG - Tesefy
Chainsaw pickup - TG5
Shotgun pickup - LFW, Skelegant, Gem, myself
Super shotgun pickup - TG5
Chaingun, rocket launcher, plasma gun, BFG9000  pickups - Tesefy, myself

Armors - Tesefy
Stimpack, medikit, berserk - Nathan Silver, with slight edits by myself on the stim and medikit
Clip - Made by myself
Shells - Skelegant
Rocket - Skelegant, with edits by myself
Shell box, ammo box, rocket box, cell, bulk cell - Zrrion the Insect
Armor and health bonus - Doomer Blazkowicz
Backpack - CyberMonday

Sounds:
Most sounds come from Squig's weapon sounds collection, which themselves come from Insurgency Sandstorm (I think)
A few sounds from Fallout New Vegas, Quake 4, Unreal Gold, Unreal Tournament 2004 and Per Kristian's HD Doom sounds have also been used