Outcry over the contents of an educational game about the slave trade has seen a segment of the game voluntarily removed.

However, the game’s developer has expressed disappointment over the furore, and condemned those who call his studio racist.

Playing History 2 - Slave Trade has been available on Steam since September 2013, but a recent promotion saw it catch the eye of several people unhappy with some of its content – namely, a Tetris-like mini-game wherein the player stacks slaves into a boat.

“Travel back in time to the 18th century and witness the horrors of the trans-Atlantic slave trade firsthand,” reads the description of the game at the Steam store.

“In this episode, you will be working as a young slave steward on a ship crossing the Atlantic,” “You are to serve the captain and be his eyes and ears — reporting any suspicious activities is your duty. But what do you do, when you realize that your own sister has been captured by the slave traders?”

Last weekend a number of people reacted in anger to Slave Tetris, with some suggesting it was "dehumanising" and "sick".

Serious Games Interactive CEO Simon Egenfeldt-Nielsen subsequently removed the offending mini-game, but under duress.

“The key reason for removing tetris was that it overshadowed 99.9% of the game, and that was not the way we wanted to sell it,” said Egenfeldt-Nielsen.

“Also it was never the intention for the game to become something that people would outright dismiss based on that single small feature.”

Egenfeldt-Nielsen acknowledged that a lot of people were appalled by the game, but said it was supposed to be educational.

“We have done this in the past with games about the Israeli-Palestinian conflict, sweat shops in Bangladesh, modern slavey in Bolivia to mention but a few,” he said.

“People are so eager to just jump on a wagon. I think the situation we have where people behave this way is far more worrying than any game that could ever be made.

“We are going towards a closed society, where sensitive and controversial subjects are not welcome in public because it causes an outcry focusing on motives and persons rather than the subject which stops any open debate.”

He also argued against those claiming that it wasn’t possible to make a game about something like the slave trade.

“This is similar to people saying you cannot make visual novels of difficult subjects or movies like Schindler's List because movies are entertainment medium,” he said.

“You can express any idea through any medium.”

You can read his responses to the main criticisms of the minigame here.