Update #2 has been released that hopefully will improve performance and gameplay. The official patch notes can be viewed here: http://steamcommunity.com/games/405830/announcements/detail/575740768226142774

Here's some additional information regarding the patch:

Singleplayer Weapon Changes
Shredder: damage decreased from 8 to 6. Scatter projectiles no longer trigger events and no longer bounce again when hitting actors.
RazorWind: damage is reduced by 75% when damaging the Mother, Queen, and Primagen bosses.
Charge dart: consumes 1 ammo for the first 5 levels of charge. Consumes 2 ammo on 6th level of charge. Consumes 3 ammo on 7th charge level.

Multiplayer Weapon Changes
Pistol: damage increased from 10 to 16
Mag60: damage increased from 14 to 17.5
Firestorm Cannon: damage increased from 3.75 to 7.5
Grenade Launcher: damage increased from 40 to 50. Damage Radius increased by 25%. Water Damage Radius increased by 250% to match non water damage radius.
Plasma Rifle: bNetSpawned and bNetLatencyComp flags added to particle. Firing Animation speed plays twice as fast.
Scorpion Missle Launcher: Firing animation time takes twice as long. damage increased from 20 to 50. Damage Radius increased by 25% on default/water/stone. Damage Radius increased by 187% on Humans/Creatures/Slime and when it's destroyed to match default/water/stone radius. On pickup, ammo has been reduced from 12 to 4
Shotgun: damage increased from 8 to 9. (13 bullets shoot out for a total of 117 damage at point blank range)
Shredder: Damage decreased from 8 to 6. Scatter projectiles no longer bounce again when hitting actors.
Charge dart: consumes 1 ammo for the first 5 levels of charge. Consumes 2 ammo on 6th level of charge. Consumes 3 ammo on 7th charge level.
Cerebral Bore: On pickup, ammo has been reduced from 10 to 1

N64 Multiplayer Weapon Changes
Assualt Rifle: damage increased from 14 to 17.5
Grenade Launcher: damage increased from 40 to 70. Damage Radius decreased by about 14%
Plasma Rifle: Impact damage increased from 40 to 80. Active damage increased from 4 to 8.

Enemies
Raptor: initialScale changed from 0.332031 to 0.5
SwampWasp: radius changed from -3.071999 to 3.071999. Start Animation changed. Other starting paremeter changes.
Turrents will no longer fire at you when they don't have a line of sight

Scripting
new class: kClipInfo
new WorldComponent method: void HitScan(kClipInfo&out, const kVec3&in origin, const kVec3&in targetOrigin, const uint EnumClipFlags, const float=0)

Audio
All instrument sounds files have been removed.