A stat I would like to see
It would be neat to have a point system where every item and every upgrade counts for a point. If I buy a goldmine it is worth 1 point. Each upgrade on that mine is worth 1 point. If I took the mine to level 11 I would have 11 points, 1 for building it and 1 for each upgrade. If you did this for every item we build and upgrade you could actually gauge how far along you are in the game. eg. you could be at 2643 of 12450. The total number of points would be very large, but you would know how you are progressing. Supercell could even include items like builders huts and the trophys which cost gems, perhaps inspiring people to spend gems to attain a higher level.