I have read the other reviews and can't but wonder whether some of the frustrations result from the versions they are playing. The parser is not so problematic in the TRS-80 versions of the program. These machines often ran in all caps mode (the original TRS-80 didn't have uppercase characters and the TRS-80 MC-10 never had them). Apparently there were also changes made to the puzzles in many of the unofficial versions. The TRS-80 version I ported remains entirely true to the original TRS-80 16K version.
There are some intentional inconsistencies to the movement in the game. I didn't find them all that bad (especially compared to some other games from the era). For the most part I think they were carefully chosen and meant to enhance the effect of being "lost in the jungles and savannas" of central Africa. To a large extent, I think this technique works successfully in this adventure, where the setting makes it appropriate to use. Once I had some mapping in place, it wasn't all that problematic and there is a kind of logic to the backs-and-forths.
There are some really charming aspects to the game. The quicksand graphic is a wonderful piece of TRS-80 chunky pixel 8-bit animation. (Spoiler - click to show)If you die the program simulates a return to the basic command prompt, before surprising you with a resurrection to a restore point part way into the game (preventing a need for a complete restart.
The game is challenging and doesn't have any of the totally arbitrary deaths that are so common in games from this genre. I found the plot to be a nice balance between slightly humorous almost fantastical whimsy and and an attempt to remain true to the Victorian mythology of the quest for Dr. Livingston.
For fans of 8-bit Basic adventuring I would highly recommend this game. But for less hardy souls, it might be better to stay away from venturing into the dark heart of the Victorian imaginary.