Throughout Crystal Caves 2 and 3,
Commander Keen's Green
Bay Packers helmet makes a few appearences
in some slime pits. You can read the story behind the
helmet's appearence at the Apogee
FAQ.
Invasion of the Yorps!
In the Galactic Encyclopedia (a.k.a
Story), the first sentance reads,
"Mylo scours the universe in search of anything he
can sell that will make him a buck and keep him from
joining his uncles Yorp herding business."
This sentance makes refrence to a particulair alien which
featured in Commander Keen (Episode One): Marooned on
Mars. A Yorp is a small, green, one-eyed being which
really isn't harful to humans (or, at least, Commander
Keen and his family).
This is what a Yorp looks like:
Top Intergalactic Traders
In the default High Score table, there
are five names listed below the Ordering Infomation (as
seen in the screen above). The full names of these are Indiana
Jones (of the Indiana Jones movies), Billy
Blaze (a.k.a Commander Keen), Snake
Logan (hero of the Bio Menace trilogy), Duke
Nukem (hero of the Duke Nukem games)
and James
Kirk (Captain of the Enterprise in Star
Trek)
Epic takes Apogee's advice
Jill Underground's
message
Crystal Caves Message
In various levels of each volume of
Crystal Caves, there's a helpful message stating that
'Winners don't use drugs'. In the second volume of Epic
Games' Jill Trilogy (titled 'Jill goes Underground'),
there's a sign stating that 'Winners don't lose frogs'.
Could be Epic poking fun at an(other) Apogee game?
Probably.
(Thanks to LevelLord00 for this information)