Invincibility -
Enter "CH3T" as a password.

Start a highest level previously reached -
Enter "W4RP" as a password.

View credits -
Enter "CR3D" as a password.

Level passwords -
Level - PASSWORD
1 - NTR0 
2 - 1STS 
3 - 2NDS 
4 - TRSH 
5 - SW1M 
6 - W0LF 
7 - T1M3 
8 - K4RN 
9 - B0MB 
10 - WZRD 
11 - BLKS 
12 - TLPT 
13 - GYSR 
14 - B3SV 
15 - R3T0 
16 - DRNK 
17 - Y0VR 
18 - 0VAL 
19 - T1N3 
20 - D4RK 
21 - H4RD 
22 - HRDR 
23 - LOST 
24 - 0B0Y 
25 - HOM3 
26 - SHCK 
27 - TNNL 
28 - H3LL 
29 - B4RH 
30 - B4DD 
31 - D4DY