This is the most balanced map I've made (The old version was like...well, un-balanced). The resources on this map are a little less that what you'd like, aka, made for better players, not newbies. Colonies are either 6 mineral mines/1 vespene geyser/4 mineral mines and 1 vespene geyser. And yes, there is a nice area of 12 mineral mines and 2 vespene geysers in the middle, which is quite vulnerable. Have fun!