Currently stuck on this game and I cannot get past Level 30. I know what to do, but I can't figure out the switch combination needed to successfully get through it.

To pass it, you first have to go Level 26 and go to the top-left teleporter. Make your way through all of the slugs and shoot the eyes. Use the teleporter and then go on a platform to make your way to the switches at the top.

I don't know which switches to press at this point, even though there's a hint message to the left of the teleporter on Level 26 that's to be used for the switches on Level 28.

Finally, in case anyone wanted to jump ahead and see later levels for themselves, here's a complete list of passwords ripped straight from the game via RAM editing:
kebdfal - Level 6
gkefklb - Level 11
ffjgfke - Level 16
dhjccjb - Level 21
ggcebik - Level 26
jidkeia - Level 31
ajgdlgi - Level 35
lhhdllc - Level 36
ehgekec - Level 41
aghdach - Level 46
kcibbjl - Level 51
gkbafcl - Level 56
clijfdi - Level 61
bjkkaij - Level 66
ajieghi - Level 70
algagka - Level 71
dhifaab - Level 76
agjdleg - Level 81
ehjggbe - Level 86
iahdbdc - Level 94

The rest of these appear to be dummy passwords with no apparent effects, as these just send you to Level 1:
jialidb
aggjjgl
iagieea
abgbjjl
kiijkbb
fblccbe
jddaecf
jjhdkbl