To get invicibility in the demo version simply hold command and type INVINCIBILITY.
Level Select
Here are some level select passwords:Falcon, Anoat, Yuzzem, Brigia, Greedo, Biggs, Kaiburr, Mynock, Dagobah, Mimban, Ackbar, Fornax, Beepin, Kessel, Organa.
Normal Version
Here are the codes for the Normal level of Rebel Assault.
These codes work at very least for the Macintosh version:
1. BOTHAN
2. HERGLIC
3. LEENI
4. THRAWN
5. LWYLL
6. MAZZIC
7. JULPA
8. MORRT
9. MUFTAK
10. RASKAR
11. JHOFF
12. ITHOR
13. UMWAK
14. ORLOK
15. NKLLON
Power Mode
Hold down the command,shift,ctrl and option keys and triple
click between the "rapid fire" and "shut down other
applications" buttons while in the "Game options" window.
This will enable "Yodas Power Mode." During the game the
keys 1-9 above the keyboard and a-f enable you to skip
levels, esc key lets you skip level by level and the "+"
key on the numeric keypad repairs your damage.