Dark Continent is a MS-DOS adventure game and © 1986 by Conrad Button and ButtonWare, Inc.
Review by David Welbourn (originally posted at IFDB)
Dark Continent, frankly, is a bit of a mess. In distant echoes of Infidel, you've been abandoned by your hired help in Tunisia during your quest for a big-ass diamond, but you're an asshole and are determined to get the diamond anyway and take it back to jolly ol' England. During your quest, you'll visit minimalistic versions of Lake Victoria, the Sahara Desert, the Red Sea, and a Ubanghi village.
The first sign of trouble was when I climbed a palm tree (just because) and discovered... motor fuel. Buh-whu? What was that doing there?
When I later found an airplane, I was a quite stymied on how to use the fuel with it. This is one of those old two-word parser games, USE isn't a valid verb, there's no description for the plane, and POUR FUEL only responds with "where?", which made me think (incorrectly) that I needed to rephrase my command. Heck, I didn't even know for sure that the plane needed fuel in the first place. Dear reader, I confess I turned to the walkthrough and discovered that that "where?" was a disambiguation prompt and that I should next type IN TANK. Which I thought somewhat unfair, since the tank hadn't been mentioned anywhere at all.
The rest of the game, alas, is little better. Figuring out how to pay for the way home is severely underclued, and one puzzle is a very deliberate guess-the-verb and there's absolutely no justification for it except to make the game harder. Plus, your character has few morals and will need to perform a few despicable acts before success can be claimed.
Winning this game made me feel dirty.