Im not sure which platform but I played it in primary school maybe years 2007-2011.
I was a two player game in a dungeon or sewer and I remember there being like green acid. It was one screen with different platforms and I think the objective was to get to the bottom. Im pretty dure one of the characters was a king too.
The game was 2d and had different platforms similar to mario and donkey kong throwing barrels. Like that design with different floors. I think the objective was to get into the green slime or acid.
Im british if that makes a difference.