Test information 
Enter 
THDTST
as a password.

Unlocks all characters in multi-player mode
Enter
VRCLN
as a password.

Level -- password 
 
Attack -- LNLGRMM 
Spy Blue -- TRGHTR 
Bathroom -- TDBWL 
Riff Mission -- MSTRMN 
Forest -- TLLTRS 
Hoover Mission -- SCRDCT 
Thick Mission -- STPDMN 
Snow Mission -- BLZZRD 
Shrap Mission -- SRFPNK 
Fort Plastro -- GNRLMN 
Scorch Mission -- HTTTRT 
Showdown -- ZBTSRL 
Sandbox -- HTKTTN 
Kitchen -- PTSPNS 
Living Room -- HXMSTR 
The Way Home -- VRCLN 


Unlocks all characters in multi-player mode
VRCLN