I love building things so engine-builder games generally leave me very satisfied.  I'm currently designing an engine-builder called Brewin' USA: Taproom Takeover. Since I've been playing a lot of these games, I am writing down some thoughts on favorite and popular games with this mechanic.  I plan to start a design diary on Taproom Takeover so constructuing an informed written opinion will be helpful to me.  I hope it's helpful to you as well if you're going to design an Engine-Builder game.