Type TRONIX as password and then you have in the game:

 [F1]   Shields
 [F2]   Small bombs
 [F3]   Keys
 [F4]   Large bombs
 [Del]  Jump to the next level

 Level codes:

 Level   Code
 ----------------
 2       MEDIT
 3       KRATTY
 4       MIRATES
 5       ARRAX
 6       JANIR
 7       TRINOS
 8       SIXAN