Hideo Kojima has a lot of ideas in his head. I mean, clearly, since we have a host of upcoming Kojima games already announced, with Death Stranding 2: On the Beach, OD, and Physint. But even outside of game concepts, he can come up with a lot of weird ideas, his latest being the idea of the "forgetting game," which will have the character forget information and abilities if you take breaks from playing the game.
This new idea was mentioned in the latest episode of Kojima's Japanese radio show KOJI10 (and translated by IGN). Kojima said that you would have to play through the game quickly; otherwise the character will forget details such as "how to fire their gun or what their job is," saying that "players would have to take a week off work or school to play it."
