Dancing Stormtroopers:
Find the location in The Sewer (Chapter 12), section 4 where your partner states "That's our way out of here, let's go." Hold C + T, then immediately hold A. Keep holding all three keys until the next FMV sequence starts.

Dark Side mode:
Enable the "Force mode" and "Yoda's Power's" codes. Press [Option] + V during game play. Enter JOINME as a password to enable Dark Side mode:

Result - Code:

Super pilot status (Option) + S
Take a screenshot (Option) + C
Toggle debug mode (Option) + D

Force mode:
Press [Option] + V during game play. Enter LETGO as a password to enable Force mode:

Result - Code:

Decrease damage [+] *
Increase damage [-] *
Extra life (Option) + E
Unlimited lives (Option) + L

Passwords
Press (Ctrl) + L at the main menu. Then enter one of the passwords below.

Beginner
Chapter Password
01 (none)
02 JABBA
03 ENDOR
04 LACHTON
05 BORSK
06 KROYIES
07 AURIL
08 KAMPL
09 FERRIER
10 GALIA
11 DENARII
12 SADOW
13 ONDERON
14 ALEEMA
15 CATHAR
End DOMINIS

Novice
Chapter Password
01 (none)
02 EWOKS
03 CHEWIE
04 DANKIN
05 NOGHRI
06 CHAMMA
07 BOGGA
08 INCOM
09 KOTHLIS
10 KRATH
11 SIOSK
12 ADEGAN
13 AMANOA
14 AMBRIA
15 SYLVAR
End MIRALUKA

Standard
Chapter Password
01 (none)
02 BANTHA
03 KATANA
04 DENGAR
05 PELLAEON
06 ITHULL
07 STENNESS
08 MYRKR
09 CHURBA
10 ARTOO
11 SATAL
12 LOBUE
13 DENEBA
14 STURM
15 CRADO
End CARRACK

Expert
Chapter Password
01 (none)
02 ANAKIN
03 KENOBI
04 FORTUNA
05 MODON
06 OMMIN
07 REKKON
08 SHAZEEN
09 KIIRUIUM
10 GUNDARK
11 DIANOGA
12 ATUARRE
13 ESSADA
14 PAPLOO
15 NASHTAH
End PESTAGE

Custom 1 and Custom 2
Chapter Password
01 (none)
02 WOOKIEE
03 DROID
04 RODIAN
05 BPFASSH
06 KSHYY
07 TORVE
08 SLUISSI
09 PALANHI
10 DROKKO
11 NATTH
12 SABACC
13 ANDUR
14 ARAKANIA
15 DIATH
End DREEBO