At first i was greatly interested, i had similar ideas to learning languages like this myself. However after just a single minute i was already sick of it. There was no "fun" in the learning. For example, the first few 'games' were about learning colors(which i admit, is interesting that no english is being used to learn here) but there was no connection the player can make between the colors, the words and the pronunciation. It just "is". In other words, it's just memorizing, which is the worst way to learn something.
I will tell you an example, that made me come up with ways to learn something. You know there are 8(+ pluto) planets in the solar system, right? But how should a person remember the names and possibly the order? Well, at some point i noticed i remember the names(and a tiny bit the order as well) from the anime Sailor Moon, in which the characters are named after the planets(and divided by inner and outer planets, by order of appearance). Thus since the viewer gets into the story and characters, they automatically learn the name of the planets.
That concept could be used to learn languages as well. Like, if we go by the "colors" example, it could be an RPG in which different colored monsters need to be beaten. The player has to gain info. Like, when you get the mission, you see the image of the monster(a blue one), then you have to find someone who tells you this monster is called "Blue", and finally someone that tells you "Blue can be found at the north"
something like that, you know?
If i just needed to memorize something, i could just as well open up a Korean dictionary