Could be the early workings of Donkey Kong Country?
Although the description of the game is pretty vague, I believe that this was going to be a 2D platformer instead of a traditional arcade game. My reasoning is that Nintendo wanted to expand the Donkey Kong franchise, and they knew a platformer would be more successful than a traditional arcade game. So I imagine they tried to develop a 2D platformer where Donkey Kong could jump and throw barrels just like in Donkey Kong Country. However, similar to how they tried to implement Yoshi on the NES, they realized that the hardware simply couldn't handle it and scrapped the project; where it would later result in Donkey Kong Country for the SNES.