Five years in the making, Heart of Darkness is the latest platform/puzzle game from the creators of Out of this World and Flashback. It's a subgenre where the only real competition is GT's Oddworld series, which it mirrors in its high-quality, brain-twisting puzzles. The story is all Steven Spielberg meets Jim Henson, though not nearly as annoying as that might sound. Boy from the suburbs uses his self-made spaceship to travel to another world to save his loyal cartoony dog, who's been kidnapped by a shadowy netherworld ruler. After boy crashes, he has to hoof it the rest of the way to the castle his pal is imprisoned in. Barring his way are crazy alien environments, which are the home to kid-eating lake monsters, slime-drooling spiders, nebulous winged demons, and the like. The puzzles involve getting past all of them, often by performing tasks over several different screens (the game moves screen-by-2D-screen, instead of with a gradually scrolling view) in precise order before you can proceed further.