You can watch add-on's trailer before reading here: 

Armor

Addon has only 1 armor set now - B-01 Tactical, the default helldiver's armor and a default cape

Guns

All guns mechanics:

• If the gun is empty to reload you have to have a right magazine in you hotbar. If ypu want to reload while still having ammo you need to put a magazine in your offhand and use the gun, but all remaining bullets will be wasted
• Most of the guns have flashlight on them, to activate it you need to put a "flashlight" item to your offhand
• You can change firemode on some guns by pressing crouch+attack
• Ammo indicator is shown on the picture below

AR-23 Liberator

• Damage - 4.5
• Melee damage - 6
• You can change firemode to burst

AR-23P Liberator Penetrator

• Damage - 5
• Melee damage - 8
• You can change firemode to burst

MG-43 Machine Gun

• Damage - 8
• Melee damage - 6
• You can change firemode to lower fire rate

P-2 Peacemaker

• Damage - 6
• Melee damage - 3

EAT-17 Expandable Anti-Tank

• Impact damage - 150
• Area damage - 100
• Radius - 4 blocks
• Can be shot only one time

Stim

• When used clears your effects and gives you regeneration for 12 seconds and speed boost for 10
• If you stop using it before the animation end you won't get effects
• Not a gun but I didn't know where to put it

Stratagems

Offensive

Eagle Airstrike

• Drops 4 bombs in the area near the place you've thrown the stratagem
• (idk how much damage it does xd)

Eagle Napalm Airstrike

• Same as regular airstrike but bombs make fire in a big area around themselves

Eagle 500kg Bomb

• Very powerfull explosion but with a fast damage loss from distance

Orbital Precision Strike

• Powerfull direct hit from orbit

Supply

MG-43

• Drops, well, MG-43 Machine Gun in a hellpod
• When you take it you recieve 2 machine gun magazines as well

EAT-17

• Drops 2 EAT-17s in a hellpod

Resupply

• Drops a hellpod full of supplies
• 1 supply box gives you 10 AR mags, 4 pistol mags and 2 mg mags

Emotes

Of cource, salute

• Just hold the item "salute" your hand and enjoy democracy

Handshake

• One person should hold item "handshale" and the other should interact with him while standing close

Enemies

Automatons

Automaton trooper

• Fires bursts of 4 shots
• Damage - 5
• HP - 20
• Sometimes their bullets will give you slowness(brocken leg)

Automaton brawler

• Melee enemy
• Damage - 10
• HP - 20

Automaton commissar

• Fires single shots
• Damage - 5
• HP - 20

Sometimes if there are 6 or more automatons near they will start singing