Basic "Shop" mechanics

There are now shops you can buy things from! Specifically, you can buy "max energy" and "max fuel" upgrades, "trinkets", and most importantly, unlock new ships.

So, all 15 types of ship can now actually be played with.

In the "Rock" area's shop, you can buy Miner and Bore ships, which produce gold by mining and shooting asteroids respectively. So that's going to be the easiest way to get a lot of gold for now. (Those ships are correspondingly much more expensive than the others.)