If you are knocked back, you can slow down your movement.
Teching
C
Sector 7
Activate before receiving damage to minimize knockback effect.
Reboot
Hold ↓ then C C C C Z
Sector X
Resets stats to initial values, refunding points spent on them. Most health and ammo are lost, and you can't regain HP from health upgrades for the rest of the sector. Armor, however, is reset to full. You can't use this during a boss fight.
Retribution
C
Sector 8
Activate after being damaged to create a powerful retalitory attack. Can only be used if you have less than 5 HP, and consumes 1 ammo of each type. Usable only once per boss or sector.