Phlinx To Go pack.dat (ARCPACK?)

[JeffMakesGames]

Any idea how to look inside this archive?

It's from an old old old game called Phlinx TO Go.

http://www.jeffmakesgames.com/misc/pack.dat (10mb)

I tried Xripper and it didn't see anything.

I looked in the header of the file and I see 'ARCPACK'.

I looked in QuickBMS scripts and see a script for such a thing (http://aluigi.altervista.org/bms/playpond.bms - ARCPACK\0) but it doesn't work. It's almost an exact match I think, but not quite.

Any ideas?

This is what happens when I run that script:

[aluigi]

I suspect it uses a different key, extraction fails if we ignore that byte

[JeffMakesGames]

Is there a way to discover the key?

[aluigi]

I don't even know if it's just the matter of the key.
It may be a completely different algorithm.
Just supposing.