Many good suggestions in here already, so I'm just gonna add Space Engineers. It's a voxel-based spaceship building game, where you can quite literally design

Many good suggestions in here already, so I'm just gonna add Space Engineers. It's a voxel-based spaceship building game, where you can quite literally design your spaceship from scratch. If that's not enough for you, you can interact with your creation by writing c#-scripts that are stored in physically accessible programmable blocks. There's also a large modding community you can get into.