Unlock Nemesis:
Complete the game to unlock the Nemesis as a character model.

Unlock Evil Boss Body:
Complete Single-Player in Campaign mode to unlock the Evil Boss body.

Hidden Chat and Waiting Room Taunts:
When you enter a chat room or waiting room on XBox Live click and hold the Left analog-stick and press X, Y, L or R.

Unlock Nemesis:
To unlock Nemises as an available character model beat the single player campaign successfully.

Quick Neurohack Defence (Team Matches):
Mechs with reactive and reflective armour should hoard those abilities during team matches to throw off enemy battlearmor attempting to Neurocheck.