Ancient Cave mode is a hoot. Rebuilds EarthBound as a dungeon crawler utilizing existing maps and even balances things to where you roughly should be in power. A great twist for those who have mastered the game and want more mileage out of it! Not to mention it a crazy, surreal game even more crazy and surreal.
Watch DDDDDBDDDD (EarthBound Randomized) Part 1 from spoonshiro on www.twitch.tv
Try it out for yourself!
Here's the seed and options I used if you want to try a copy of this exact hack:
And just for fun, here are the maps I've made so far. Each Shining Spot boss indicates the end of one of the nine "floors" of the dungeon.