Now - a foreword; this is all going on the assumption that
the level codes at GameFAQs are accurate. I cannot find another source either confirming or disproving that assumption (though I didn't look super hard). I do notice two codes are an extra character long; these might be typos, or errors in the game.
But there's some interesting messages in the codes, for sure.
First, here's the list of codes, in actual level order (GameFAQs uses alphabetical order, which is slightly wrong here):
02 STARTING
03 DIFFRENT
04 PLECTRUM
05 ROBINSON
06 GREGATIM
07 FUNCTION
08 BLANDISH
09 LAMPWICK
10 MURLITION
11 SURPRISE
12 TRAPDOOR
13 FIGUERAS
14 SANDWICH
15 BATEMANS
16 PANGOLIN
17 GARGANEY
18 PECULIAR
19 ESPANOLA
20 WOBEGONE
21 TRISTART
22 SHOBNALL
23 CURLICUE
24 BILLYCAN
25 GOLDPEAK
26 GRIPPING
27 FUGITIVE
28 FEARLESS
29 SPITULUM
30 BESLAVER
31 ANABLEPS
32 QUINCUNX
33 TARLATAN
34 YANGSING
35 GUMMOSIS
36 PRODNOSE
37 NGULTRIM
38 COTTABUS
39 THANKSTO
40 BIERHAUS
41 TAXSTART
42 AFBAMIXS
43 BRADFORD
44 SHEEPAND
45 SMARMITE
46 CHEAPGAG
47 THINKYOU
48 PROBABLY
49 CANTREAD
50 NEXTONES
51 TSTDFWTO
52 HOHOOHHF
53 EMAWROAT
54 SETNTETH
55 ECRWHNSA
56 AOEAOJON
57 RDARSORG
58 EEDDEYTX
59 XSXSXXXX
60 FOOTBALL
61 MAYSTART
62 TASHKENT
63 ZULUDAWN
64 QUATRAIN
65 GRANDCRU
66 WITTMANN
67 WHATNEXT
68 UNCTIOUS
69 EVERARADS
70 ENTREATY
71 GLACKIAN
72 WHEEEEEE
73 IKEIMMEL
74 MORROCCO
75 TWOPOINT
76 FOLLICLE
77 SPROCKET
78 METARULE
79 FALLBACK
80 BEANCURD
Of particular interest are:
21, 41, 61: TRISTART TAXSTART MAYSTART - note these are the first levels of Tricky, Taxing and Mayhem respectively (hm, wonder if the unlisted code for level 01 is "FUNSTART"...)
39 and 40: THANKSTO BIERHAUS
46 to 50: CHEAPGAG THINKYOU PROBABLY CANTREAD NEXTONES
51 to 59, these need to be arranged vertically:
TSTDFWTO
HOHOOHHF
EMAWROAT
SETNTETH
ECRWHNSA
AOEAOJON
RDARSORG
EEDDEYTX
XSXSXXXXReading this top-to-bottom, left-to-right, and dropping the X's, this reads: "these are some codes that read downwards for those who enjoy that sort of thang" [sic]
Also, code 72 is WHEEEEEE. Not so much of an easter egg in and of itself, but both myself and GigaLem found this highly amusing.
I couldn't find any mention of this anywhere with a quick Google search. Is this known?