I don't want to vote negative and not contribute anything positive. So here's a list of past strategy games where I enjoyed the theme a lot. But you can ignore this if it's not actually helpful. ;
- Evolution: improve your monster species for typical 4X goals.
- Gardening Tournament or drive to earn X$ by day Y by efficient worker placement and upgrade purchasing/filling orders in a farm or garden setting.
- Factory/Tailor/Pet Breeder: produce objects or items to fill customer orders before the customers get impatient and leave.
- Caveman Town Builder: Like an RTS single-player mission without combat, the goal is to complete mission objectives as fast as possible, and mission objectives generally involve constructing and upgrading buildings, collecting resources, building up population, or removing obstacles.
- Insect hive/insect-like alien hive: build up your base and unlock new unit types to grow from being a single insect to being a fully-staffed hive. Probably this would alternate sandbox play in the hive and strategic play outside the hive.
- Produce a complete set by experimenting with recipes or crossbreeding; this could be pet breeding again, or it could be cooking or creating jewelry or paintings (automated by the game, not realistic artistic creation).
Phone game idea available free to someone who will develop it (Alphadoku game - the only existing phone game of this type is both for windows phone only and awful. PM for details.)
I want to help design a "sandpark" MMO. Optional interactive story with quests and deeply characterized NPCs, plus sandbox elements like player-craftable housing and lots of other crafting. If you are starting a design of this type, please PM me. I also love pet-breeding games.