SUPER DOOM BROS:
a dumb arcadey Mario inspired mod with a "co-op" feature based on how super mario 3D world handled it: At the end of the stage, the player with the most points was given a crown, adding a backstabbing competitive element quickly after beating a stage.

This could be worked into doom by punching your teammates in the face to make them drop the crown, or somehow make an enemy kill them (revenants)

players would be armed with a subweapon and melee weapon at all times, slot 1 would let them access both at the same time, when another weapon is equipped, the player can switch between the sub and melee weapon by hitting the USE ITEM key, which is then used with altfire.

To further add to this, players can only carry one rifle (shotgun, SSG, machinegun, etc), one heavy weapon (plasma gun, rockets, etc), and one special (BFG and other high tier or crazy weapons)

both subweapons and melee weapons have the potential to use ammo, to keep things interesting for the players.

Unless otherwise mentioned, subweapons and melee will have infinite use

SUBWEAPONS:

Rocks: These kinda suck and they travel in arc after a distance, but it beats nothing, and hey, someone's gonna try killing a cyberdemon with rocks, and that's funny. Doombros start with these.

Boomerang: You throw it, it comes back! Less range than most subweapons, but does good damage and can cause paralysis if you refrain from throwing it for a bit.

Pistol (uses bullets): an old classic, now slightly less shit, shoots at a good steady rate, accurate, and does a little more damage than the vanilla counterpart.

Laser gun (uses cells): First shot is a bigger, harder hitting beam before unleashing a surge of rapid pulses

Flare gun (uses rockets): fire a rocket propelled flare at targets, explodes and leaves little flames on hit

Sawn-off shotgun (uses shells): "both barrels for you bastards!" fires a projectile spray of pellets

Red devil flower: Throw fireballs like everyone's favorite plumber!

Green devil flower: Throw fireballs like green mario! Not affected by gravity

Bow: old school, requires the player to hold fire down to charge up arrow, otherwise doesn't travel very far or do good damage

MELEE WEAPONS:

Fist: GIVE EM THE OL KNUCKLE SLAMWICH, all Doombros start with this! (I sure as hell would hope so)

the Shiv: Cut bitches up with a triangular knife, if attack is held, player can throw the knife for moderate damage but it'll leave them without a knife for about 5 seconds

Chainsaw: find some meat!

Climbsaw (heat meter): CLIMB some meat, and walls too

Gun glove (uses shells): punch AND shoot at the same time, only fires on hit.

sword: get medieval on their ass, hold attack to charge up a spin attack

Wrist barrier (uses cells): project an energy field to protect yourself (and your fellow Doombros, if you want), after releasing, causes a small burst effect

whip: when a demon comes along, you must whip it! Does more damage at the tip when it snaps

BattleDoomer fists: Throw out rapid jabs that end in a powerful finishing blow!

health potion (15 second cooldown): Toss out a special health bonus that gives slow health regen, gives Doombros about 20 HP overtime