An excellent stylistic game made by the french company Amazing Studio. The company was also known as Delphine - famous for the old classic games of all times like Another World and Flash Back.
Heart of Darkness looked really impressive at the time. A video teaser of the game was released during 1994 which showed impressive animation graphics similar to those of big USA companies Nintendo. However the game took 7 years to come out being released in 1999. At the time of release the game was outdated with outdated 2D graphics/animation and platform gameplay. If it had been released during the teaser release in 1994 it would have rocked and the company wouldn't have gone into liquidation.