Extra explosion damage

Enter ACMEBANGS as a password.

Enemies less aware

Enter COLDFEET as a password.

Multi-player linkup

You can link up a Game Boy Advance with Ecks vs. Sever and a Game Boy Advance with Ballistic: Ecks vs. Sever 2 and still play all the multi-payer modes. The level combinations between the games are slightly glitched, but it still works.

Invincibility

Enter DEATHWISH as a password.

Unlimited ammunition

Enter BIGPOCKET as a password.

All weapons

Enter TOOLEDUP as a password.

One shot kills

Enter OOHSTOPIT as a password.

Rapid fire for shotgun

Enter MYBIGUN as a password.

Invisible mode

Enter DOYOUCME as a password.

Alternate sounds when hit or killed

Enter HORNBLOW as a password.

Levels

Level/ Ecks/ Sever

2/ SMOKEY/ RAVEN
3/ BUTTERFLY/ FIREFLY
4/ COVEY/ BULLDOG
5/ TIGER/ DRAGON
6/ HORNET/ LOUDMOUTH
7/ LITTERBUG/ STINGER
8/ MUSTANG/ NAIL
9/ SPECTRE/ ZORRO
10/ NIMROD/ XRAY
End/ SPOOKY/ REDDOG

Sever Stinger mission

On the Sever mission Stinger (with the guided missiles), find the door where a man comes out when you shoot a chemical. Stand half by the door and half by the wall and turn extremely slowly. The crossed hand will turn to a normal one, allowing you to open the door as you normally would.