YMMV / Project Brutality

• Demonic Spiders: With all classes of monsters having multiple variants, there are bound to be a couple of annoying demons to fight:
  • Riot Shield Sergeants as their name implies carry a riot shield around with them at all times. Although their main method of attack is a pistol, their shield can block any form of fire outside of acid, explosions, plasma, flame, or a berserk-infused kick. Not even a direct Super Shotgun blast can break through their shields, and they tend to appear quite frequently in early levels where plasma and explosive weapons are a rarity. The only way to dispatch them without their aforementioned weaknesses is to either headshot them, which is only possible when they aren't shooting at you, or to get just behind them, which can be difficult when the foe is always facing you to attack.
  • The Phantasm variant for Lost Souls. These green lost souls have a much faster rate of attack than their normal counterparts, can home back onto Doomguy if their attack misses the player, and will explode upon death.
  • The Cyber Paladin variant for Hell Knights. Their main method of attack is a grenade launcher arm cannon that shoots grenades that bounce across and explode upon unsuspecting players. However, like the riot shield sergeants, they also are equipped with a shield that not only blocks attacks but also launches energy wave attacks.
  • Barons of Hell have two Demonic Spiders variants under their belt. The centaur-esque Belphegors are essentially mook versions of their Brutal Doom Extermination Day boss counterparts with their larger-than-average explosive radius energy projectiles plus a devastating bull charge attack. The Inferni are hellfire-colored Barons that are constantly able to discharge 3 spike pillars that travel in a spread and can easily take off over 100 points of health from even the most unsuspecting player.
  • If you hated Arch-Viles in vanilla Doom, you'll hate them even more here. For one, vanilla Arch-Viles, in addition to their hitscan fire blast and resurrection abilities, can now throw fire waves, heal demons, and summon Imps and Afrits. The worst of the 3 variants is the Flesh Wizard, which moves around quickly and erratically and is invincible except for when it throws its blood projectile, which does a ton of damage.
  • The SS troopers are far more dangerous than their vanilla counterparts. They are far more agile, and they fire their guns on full-auto. Add in the fact that the level where they first appear (MAP31 of Doom II) has them showing up in groups, and you've got a recipe for pain.
  • While the Vanilla Cyberdemons are already terrifying and dangerous enough, this mod introduces the Annihilator, a bigger, beefier version with two rocket launchers instead of one... have fun!
• Game-Breaker: The Unmaker upgrade for the Mancubus Flame Cannon fires either a devastating beam of hell energy or a volley of destructive fireballs, making quick work of most demons before you. What elevates it to Game-Breaker status is the fact that it's NOT Too Awesome to Use: it uses Demon Energy as ammo, which Randomly Drops from most enemy types! So not only is it ridiculously powerful, it almost pays back for itself whenever you wipe out a room full of demons with it.
  • The Special Grenade Launcher's cryogenic grenades have decent damage and area effect, so they'll reliably turn a good few low-tier enemies into icicles per unit of ammo if fired into a tight group. Every frozen enemy drops a number of health vials when shattered, which will boost hitpoints by a few points each. The game-breaking effect comes into play when you realise that while every other type of health item has a cap of 200, the effect of vials is completely uncapped. In maps that have large crowds of low-level enemies, lobbing a magazine's worth of cryo grenades into a group, followed by one frag grenade or rocket, will spawn a stupid amount of health vials for hundreds of hitpoints - potentially thousands, if you're playing a slaughter map and there's enough ammo around. As long as you keep flash-freezing imps and grunts, this is almost like activating god mode.
• Genius Bonus: The weapon upgrade for the UAC-B750. 500 Revolver is the UAC-H54 ‘Martian Raptor’ Automag, the design successor to the Desert Eagle. "Raptors" are an alternative name for Birds of Prey, predatory avians which include the Eagle.
• Good Bad Bugs: As mentioned elsewhere, the GZDoom engine has buggy ways of calculating fire damage. This makes it difficult to balance flame weapons, something notoriously difficult in games as a whole; fortunately where most other games elect to err on the side of caution, Brutality just goes "to hell with it" - in a very literal sense. Basically, anything that'll do fire damage is overpowered as a matter of fact, and as a result incredibly satisfying to use. Adding to the fun, using flame weapons with abandon can often trigger an engine bug where enemies will catch on fire when killed by other weapons for the duration of the map. Shoot some grunt with a pistol, watch them light on fire and scream as they burn to a crisp.
• Hilarious in Hindsight: The mod was released in a playable form a year before Doom (2016), however, most of the gameplay elements are eerily prescient:
  • The Project Brutality chaingun has a Death Dealer upgrade that lets the chaingun open up to reveal two extra barrel clusters, allowing the triple-chaingun to shoot more bullets for massive damage at the expense of wasting more ammo. In Doom (2016), the Chaingun's Mobile Turret mod does exactly that, although the main barrel splits into three instead.
  • Project Brutality introduces Demon Essence, a common drop from non-zombie demons in the form of red spheres of demonic energy. Picking up Demon Essence not only provides ammo for some of the demonic weapons in Doomguy's arsenal (namely the Demon Tech Rifle and the Unmaker) but picking up Demon Essence can also restore a bit of armor and health to Doomguy. Doom 2016 introduces a demonic form of energy called Argent Energy as a major point of the game, which not only is utilized to some extent by most of the Doom Slayer's arsenal but also can be absorbed by the Doom Slayer's Praetor Suit to upgrade the Doom Slayer and restore health and armor to him as well.
  • The game introduced shield-wielding former humans as enemies, which was also introduced in Doom 2016 (although the ones in Doom 2016 use energy shields and wield plasma rifles instead of using ballistic shields and toting shotguns)
  • The Cyber Paladin variant of Hell Knight, which wields an impervious shield as well as being tough to kill (though not as tough as the Marauder, which by all intents and purpose is a boss-type enemy), existed 5 years before Doom Eternal introduced the dreaded Marauder.
    • Additionally, the Juggernaut (A giant armored Mancubus equipped with machine guns and rocket launchers on tank treads that occasionally replaces the Spider Mastermind) could be seen as a precursor to the Doom Hunter.
• Nintendo Hard: Having started life as an add-on mod for Brutal Doom, Project Brutality has new variants of the original enemies that deal more damage. While it does give you new weapons and tactics to compensate, the result is that gameplay still ends up being harder.