Most of these games were made available by their authors on FTP sites - which archive.org doesn't archive - or are not archived due to a robots.txt exclusion. Please help me find them.
I didn't see any indication, in the game or in the zip file, that this is a demo. Have you played it to a point where it offered ordering information or said "more levels await in the full version"?
Also, what's up with the weird readme?
To make a demo version of ZOOL2 type 'MAKE picture-file' where
'picture-file' is a Delux Paint LBM file. The two files that make up
the game are ZOOL2.EXE and ZOOL2.DAT.
Today entirely the maniac there is no excuse with the article.
I think I've figured out what the weird readme is all about. It gives instructions on how different distributors could create their own splash screens for the Zool 2 demo. Here's the Zool 2 demo that was distributed by the German PC Player magazine that has the first Gremlin logo replaced by a logo promoting the magazine.
I have a Zool 2 demo from a shareware disc, if that's of any interest. It's in a directory and not zipped. I also have a Zool 2 demo with intro and game over videos. This second demo must be played from a CD drive.