When you reach a set level, a new weapon, gear, or berserk becomes available. The weapons and berserks are unlocked upon reaching that level but the gear requires enough gray tech to purchase once you hit that level.

Unlockable	How to Unlock
Level 1	Marksmen (Weapon)
Level 1	Prototype Ammo (Berserk)
Level 10	Proximity Mines (Berserk)
Level 12	Snake Eyes (Berserk)
Level 12	L23 Fareye (Weapon)
Level 14	Shock Suppressor
Level 16	Assault Pack
Level 18	Auger (Weapon)
Level 2	Bullseye (Weapon)
Level 22	Hawkeye Scope
Level 24	Voltaic Body Armor
Level 26	Mag-Propulsion Barrel
Level 28	Bellock (Weapon)
Level 30	Psychokinetic Helmet
Level 4	Invisiblity (Berserk)
Level 6	Kinetic Gloves
Level 8	High Density Ammo Chamber