Individual credits are given in the code itself, but this is a list of everyone I 'borrowed' stuff from

* = Taken from Realm667

Powerups:

Icon of the Raven* : Ghastly_dragon, NeuralStunner, Neoworm
Ammo Sphere* : Dreadopp
Summon Sphere* : scalliano
Gems* : Mor'ladim, Brain Lord, Fate, Ghastly_dragon
ArchMorph(Sprites only)*: Scalliano
UpgradeSphere (Sprites only)*: Salahmander, MagicWazard

Weapons:

CryoBow* : ZZrionTheInsect, Bloax, Xaser, Ethril
Bayonet Rifle* : Quantum_Dranger
Dio's Knives: Taken from DIO.wad
Emerald Splash (Sprites only) : My brother and Jojo HFTF
Flamer* : Xim, Jimmy Beaubien, The Innocent Crew
Reflective Sword (Pickup sprite only): PSTrooper 
Revolver (Sprites only)* : Carbine Dioxide, Deon, KDiZD team
Static Rifle (Sprites only)* : Kirby and Captain Toenail's Insane Plasma Array
Freezino (Sprites only): Taken from Samsara
Chicken hands (Hand Sprites only): Taken from Joblez_I's post on the ZDoom Forums (https://forum.zdoom.org/viewtopic.php?t=50920&start=420)
Archvile hands (Sprites only): taken from EMPATHY.wad
Juggernaut chaingun: Eriance, Z86

Super Weapons:
Fist (Sprites only)*: TheDoomedArchvile, HacX
Pistol (Sprites only)*: MasterOFMorag
Bayonet Rifle (Sprites only)*: Skelegant
Emerald Splash (Sprites only)*: RockstarRaccoon
Shotgun (Sprites only)*: Ghastly, Blue Shadow, Eriance
Super Shotgun (Sprites only)*: DBJ87, 1337spy (Idle Sprites), Bgraybr, Warhawk
Chaingun (Sprites only)*: zrrion the insect, Ghastly
Minigun (Sprites only)*: Mr. Green, Doom 2.5 Team
Rocket Launcher (Sprites only)*: Eriance, KDiZD Team (Projectile), Ghastly_dragon, Infernus, Xaser
Grenade Launcher (Mine)*: Gothic
Grenade Launcher (Sprites only) (Weapon)*: TheDarkArchon, Ghastly, Freedoom, Nmn
CryoBow (Sprites only)*: Eriance, Ghastly_dragon
Plasma Rifle (Sprites only)*: PillowBlaster, JoeyTD
Static Rifle (Sprites only)*: Ghastly_dragon, Eriance, Mechadon/KDiZD Team
Flamer*: Amuscaria, Ghastly, Keksdose
Freezino (Hand Sprites only)*: Ceeb, Tormentor667, TheDoomedArchvile, Blue Shadow
BFG9000 (Sprites only)*: Robot J
BFG10K: NMN, Zero Prophet, Reactor, Kronos, Gothic

Graphics:

Doom Textures for Doom 2* : SargeBaldy
Final Doom Textures* : MagicWazard
Liquid Textures*: Nick Baker
Skies : Taken from Box o' skies
DrDoctor's textures*: DrDoctor
Snow Textures: Taken from Russian Overkill
Ice Textures: Taken from Whitemare.WAD
Lava falls*: Nick Baker's NiGHTMARE texture WAD 2


Music:
Map themes: Taken from Ultimidi
Title theme: a midi version of the main theme of Profondo Rosso I found on the internet a while back.


Decoration:

Terrain Splashes* : MagicWazard
Trees and bushes* : CaptainToenail, Necrodome
Doom Statues* : JMAA, MagicWazard, Captain Toenail, Gez, ShadesMaster, Shtbag667
Fire Pillars* : zrrion the insect
Cauldrons* : CaptainToenail, ShadowCaster
Office Chairs* : CaptainToenail
Czech Hedgehog* : MagicWazard
Junk Piles* : Gothic

Fonts:
Duke Nukem Font*: Jimmy