Overview
Doomguy is a hard hitting lower heavyweight character who excels at mid-range combat and ground mobility, with high dashing and walking speeds just shy of some of the Top 10 fastest characters in the game and a Mega Man-esque moveset full of projectile attacks, many of which boast extremely effective combinations of speed, range and power. The few melee attacks in his arsenal hit just as hard as his projectiles.
His weaknesses lie in his poor aerial mobility and recovery, as he is a fast faller with mediocre air speed, low air acceleration and only a single highly vulnerable, predictable recovery move. His gimmick, the Ammo System, is also arguably a weaknesses, as it slowly deprives him of the majority of his moveset and inevitably forces him into using his close range moves which, while powerful, tend to be slow, unsafe, and lacking in knockback compared to his ranged ones.
Ammo
As drawback to the sheer effectiveness of Doomguy’s ranged options, all of Doomguy’s ranged attacks, save the two that use the pistol, have a hidden ammo count similar to Robin’s limited Tomes or Levin Swords. Each weapon has it’s own individual pool of ammo and moves that use the same weapon share ammo with each other. The stronger moves tend to have low ammo counts, at 4 to 5 shots, while the weaker ones tend to have higher ones, about 7 to 8. Doomguy’s pistol is unique in that it is his only ranged option with unlimited ammo. However, it is lacks effectiveness and requires around a second of cooldown between attacks.
Upon successfully landing one of a select few melee attacks, all opponents damaged by the attack release one ammo pickup, which Doomguy automatically absorbs. Each ammo pickup replenishes ammunition for all weapons by one. As such, Doomguy must inevitably move in to land one of his slow, unsafe close ranged attack in order to keep up his ammo supply and continue using his faster, safer long ranged ones. As his melee also have weak knockback growth, he also needs a supply of ammunition to reliably finish off stocks. Yeah, it's kind of a reverse of the Doom 4 Glory Kill system, but I made it this way for balance reasons and to keep Doomguy focused on his projectile game.
Specials
B-Super Shotgun-Press B to take out the Super Shotgun and use the analog stick to aim in any direction. Release to fire. Simply tapping the button will cause it to automatically fire straight forward. Little starting or ending lag and boasts massive power at close range, but has a low ammo count and limited power at a distance. The Copy ability version automatically discards when empty like Robin;s Thunder tome.
>B-Plasma Rifle-Release a volley of about 5 plasma rifle shots. Not the most powerful of Doomguy’s guns, but has good speed, range, and a high ammo count. Each use automatically fires off the five shot volley and each volley counts for one ammo, with very little cooldown between volleys, so you can get a lot off of this. Can be angle up or down as Doomguy fires. Shares ammo with back aerial.
^B-BFG 9000-Take a quick moment to charge and then fire off a massively powerful projectile that explodes on collision. On the ground, this move angles upwards, but the projectile is large enough to pick up standing medium height characters from the ground at point black. In the air, Doomguy fires this move straight downward and propels himself into the air with the recoil. His falling speed slightly slows during the charge. This move offers no upper hitbox or protection, making Doomguy’s recovery very vulnerable. However, it does not put him into helpless state, though you have to wait out a rather large endlag before you can act again.
vB-Explosive Barrel (thanks Shinhed!)-Spawn an explosive barrel and slam it down in front of your feet, or toss it below yourself in the air. The grounded version creates a weak shockwave as Doomguy slams it into the ground, whereas the aerial version works similarly to Sonic’s spring. Once spawned, the barrel works like a less powerful version of the Blast Box item. It can be picked up and thrown by any character. Sufficient damage or a fire type attack will cause it to explode, damaging anyone nearby. Only one barrel can be spawned at a time.
Normals
A-Beat the opponent with your gun. The quickest of Doomguy’s melee attacks, though also the weakest and shortest range and still not lightning fast.
AA-Stick your leg way out and kick the opponent, similar to Ganondorf’s >A. Longer range and more power than the first hit, but bigger endling. Recovers ammo.
>A-Doomguy fires off three shots from his Pistol. Can also be used while walking like Mega Man’s Mega Buster. However, the shots lack in range and power and Doomguy must wait out a 1 second cooldown between each volley. The Plasma Rifle basically does everything this does better, but it has infinite ammo, so it’s a good last resort.
^A-Doomguy unleashes a devastating uppercut. Covers a similar angle to Ryu's up smash. Recovers ammo.
vA-Lob a grenade forward from your low position that explodes on collision or after traveling a set distance. Has a medium ammo pool and shares it with Uair. Deals fire type damage.
>Smash-Jut forward with the Unmaker and release a torrent of shots. The Unmaker has a hitbox during the jut that knocks opponents into position for the following attack. Extremely powerful, multi-hitting and mid-range, but has low ammo count.
^Smash-Knock opponents upward with a swing of the Gauss Cannon and fire a shot into the air. Moderately powerful with long range and a medium ammo count.
vSmash-Fire two rockets, one to the front and back, angled slightly down so they hit the ground a medium distance from Doomguy. If they miss the ground, they travel somewhat farther and explode on collision or after short amount of time. Moderately powerful and has a medium ammo count. Deals fire type damage.
Dash Attack-Take a big stab forward with the chainsaw. Big startup, but hits multiple times for high damage. Recovers one ammo if any of the hits land, but not per hit.
Aerials
Nair-Make a big, spinning swing with the chainsaw, swinging twice in front and once in back. The front swings are angled slightly downward, while the back swing angles slightly up. Recovers ammo.
Fair-Release are charged shot from the pistol straight forward. Somewhat slow and weak compared to Doomguy’s other projectiles, but has infinite ammo. Fires off just fast enough for Doomguy to perform from a short hop, but not fast enough to avoid the landing lag.
Uair-Lob a grenade high into the air, which will explode on collision or after a set amount of time. Has medium ammo and shares with crouch attack. Deals fire type damage.
Dair-Fire two rockets downward in an upside down “V” shape, which will explode on collision or of after a set period of time. Has a medium ammo pool and shares with down smash.
Bair-Release a scattered volley of Plasma Rifle shots. Shares a high ammo pool with forward special.
Throws
I’ll edit these in later after a bit more research, but the pummel is beating with the butt of the gun and the throws are all Doom 4 Glory Kills, all of which do good damage and recover one ammo.
Final Smash
First Person Shooter-Doomguy jumps into the air and the original Doom HUD appears over the screen. You get 12 seconds to fire off 10 powerful shots from the original, sprited BFG 9000, each shot dealing approximately 20% damage and massive knockback.