So, how is it that you get your weapon and module attachemtns and upgrades. Is it by leveling up or buy using a certian weapon to a number of kills or what. Sorry but i'm used to unlocking guns and bonuses by leveling up and that doesnt appear to be the case. It would be nice if there was a bit more explained in the directions or how to play instructions.

you didn't read the manual shipped together with your game?

lol.
every primary weapon gets unlocked by leveling.
every suit modules gets unlocked by leveling power, energy and stealth level (max 12lvl for each). upgrading them each to level 2 and 3 needs kills while
using them.
every attachments for one weapon gets unlocked by kills with the weapon.

by secondary weapons and explosives i forgot if its by leveling or killing cause i didnt care on it, just using grenades and rockets. c4 was unlocked but beacuse a bug its locked again and i cant unlock it.