There were several screenshots akin to the ones featured at the top of this thread for Abe's Exoddus. You can find several of them at the end of the Demo for Abe's Exoddus (Have a look on youtube.. there's several uploads of them) Several screen are almost identical and others slightly resemble others.. then you have the downright different ones. The ones not featured on the Demo are available on TOGG.
This one always stuck out in my mind for years..
Very different from the final entrance to Feeco.. and the Mudokons are similar to the ones featured on the first screenshot in this thread. This leads me to believe these screenshots used CAM images as backgrounds and then placed uncompressed still sprites on top to simulate gameplay.. You will find several of these screenshots contain extra enemies plastered all over the screen to make the game look more big and exciting.