Ok, one problem with this map would be the mineral lines. 12 o clock's minerals are right next to the edge of the map while everyone else's have room for scouts to move behind, giving them an advantage/disadvantage, depending on the situation/ build style.
Another thing is that there might be too much open space. You could add platforms in the lava for expansion bases with 7-8 mineral patches and 1 gas. This gives players more options and more strategies to execute. Also spice up the map with doodads to give the player a little bit of eye candy. Right now the map looks really plain and all that open space makes the mini-map tiny, which some players don't like. This map kinda reminded me of Gorky Island, lol. Ignore the last part.
Other than that you are good to go. Next time, try to make your map in a way so that it jumps out at you and WoWs the people so that they will DL it and have fun on it.

P.S: And 5 minutes? Most decent maps would take at least an hour to make. The WGT Tour map makers probably spend at least 2 hours perfecting one map. Try spending some time adding more detail to your map. If you just throw together a map and not put much thought into it, even the best idea will come out lookin' bad.