Fun concept, but progress slows pretty quickly and some items are clearly much more important than others despite costing as much as others. It feels like large trees sell for far more, and you want to cut trees into smaller logs are little as possible because of it. Carts seem like they should be more useful - They don't seem to make moving the items inside them easier, so I found myself skipping them and just dragging & selling one large solid tree, since it ends up being faster to sell, and (as mentioned above) often pays out more than the smaller logs you'd need to load a cart. Strength upgrades are absurdly useful, since you can drag the larger (most valuable) pieces to sell, and since carts don't seem to speed up moving several large objects, and add a big chunk of carry weight per upgrade Speed upgrades make a very small difference, and I never noticed a difference after several of them. Carry count upgrades only seem useful early game, when you're moving several smaller logs. As soon as larger trees were available, I found myself skipping this upgrade altogether.