Major differences to 1.7

Guns

• dual wield / two-hand weapon system
• improvements in effects/visual and faster bullets. Bullet speed is now a stat that is different per gun.
• new Weapons
• new Tool
• ammo types: some guns can load incendiary rounds. More types to come in the future.

Armor

• Damage system is reworked, damage formula is like the new vanilla formula. Damage Types still exist, and armors have different armor values against types
• Armor-penetration is now anti-toughness.

Turrets

• Turrets can now be places upside down, hanging from the ceiling.

Techguns Inventory

• new Slot: Hands
• two additional slots for ammo

Icons

• Most icons got downsized to 32x32px to better fit the minecraft style, also all non-binary alpha channels have been fixed, no more holes in item models that are generated from textures.

Worldgen

• some buildings removed, new stuff added. Will get more in the future.
• new spawners that dissapear after a specific amount of monsters have been killed.

Building Blocks

• some new stuff
• some not ported yet

Missing content

• Ore Drills (ported since 2.0.1.3_pre1 pre-release https://github.com/pWn3d1337/Techguns2/releases)