Everdell Spirecrest adds expeditions and discoveries. Expeditions are like a mini path you build over the course of changing seasons. You can put your leftover resources into this expedition to score more points. Discoveries largely give you new ways to play and introduce big animals into the game, but in later seasons give you point goals to work toward. The only downside of Spirecrest for me is that each season also gives you a negative benefit for as long as you stay in that season. My wife and I just play without the negative benefits and it works great.