Not to play captain nitpick, but if 10-20 elements in an array is okay, then a game like atoms game, as represented by larry, is already impossible. There is a grid of 96 elements.

You can't ever generate a game from procedural creation only. If I want to draw a spaceship, it requires me to create a 32x32 array and fill it with static values. But as I understand, this is not allowed.