It doesn't add anything too significant to the game, but it doesn't break it either. So there's that. You get an extra room in the house and an extra resource that's dropped randomly in the dungeon. That resource (food) you can spend between runs to get different buffs. You get an introductory cutscene about the feature, some cute animations when picking which buff to get... and that's pretty much it. Other than that, it doesn't alter the story or the game's flow. It's a nice addition, but you can do just fine without it. What makes it worth the price of admission is the charity aspect, I guess. So yeah, I'd say "so okay it's average" would be a good summation.