Your best chance for gameplay feedback is to make a map thread. This thread is hardly any different to that and will probably get less coverage. The map area is for alpha's as well as beta's and RC, so you don't need to hold out to impress anyone, it'll only hold your potential progress back.
As for the map, it looks great. But the raised tracks looks problematic. 16 is the max height players can climb as far as steps are concerned and that looks higher than 16 hammer units. Don't make players jump to reach the cart.
A Boojum Snark: Don't listen to grazr he is probably drunk