An oddity found at DLsite - this is not adult at all, but as usual, if you wander to that site, you will find some naughty content elsewhere.
It is, um... well, you have two characters and you control one with the mouse and one with the keyboard, while they attempt to constantly attack an enormous horde of tiny pixel characters wandering in and attacking you, and if you defeat them they turn into candy, and your screen is quickly littered with incomprehensible pixels and I was absolutely terrible at this and died quickly on easy.
If "weird bullet hell pixel game with devils and cake" sounds interesting, there is a free demo. And the game is actually in English... of the level of the screenshot above.
Preview the madness!