Played this through with Inferno earlier today. He was the bottom-right Terran player, I was the top-left Protoss player.
Balance notes, or based on the starting positions, I would much prefer to be the Terran player because:
- Mineral distance matters. The mining is pretty far for both players. The first thing I did was mine up to build a second Nexus closer to the minerals to fix my economy. Meanwhile, Terran can just float their Command Center over.
- The cannon closest to the minerals ends up blocking your probes once you mine enough. I had to kill my own cannon to fix my economy.
- Terran player has much more room in their base. I really don't see a reason to have top left blocked off for the Protoss player, so I would probably just open that up and move things around to have Protoss fill it out.
- Terran player has two Vespene Geysers, Protoss gets one, which is a major imbalance for any sort of melee gameplay. This is only made worse by the amount of minerals on the map, which make gas the limiting resource.
- Terran player has an expansion, very close to them, with a Geyser. They can just float there whenever they feel like, so actually make that three Geysers for them.
- Terran actually just has way more resources in general. I had to take Purple/White's base to keep mining Minerals and building late-game, but Inferno would have done fine with his main and expo. Protoss gets 14 mineral patches in their main total, Terran gets more than double in just the group of mineral patches on the left side of their main.
- Terran player cannot be reached by ground. The computer players never even attacked Terran's base once in our game.
Aesthetically, the mineral formations were pretty boring for a melee-esque map. Selecting a mineral type and holding it down for 30 patches is easy, but it's not very interesting. You have to spend more time and/or effort to get better looks. Pop open some of Blizzard's maps or play the campaign to see what some variation can do. The formations are sub-optimal for mining, but you can see how they use variation to look much prettier in the campaign by mixing mineral types in the formations. The terrain itself was pretty bland, there's a lot of rocky ground. You might want to experiment with doodad variation. Again, it takes more time/effort to look better. There's also a lot of minerals on this map, especially on the south side of the map. They feel like a space filler. (ex. Mineral Island and its opposing coastline.)
The gameplay was pretty basic and we finished in about ~33 minutes. We didn't find any bugs, but there weren't really any triggers or anything that could have introduced them. I built Carriers, (while fending off the CPUs and running out of resources), while Inferno spammed Battlecruisers and Wraiths (with no opposition and far more resources). I wouldn't have done that strategy if I knew how many Wraiths Purple had. I spent some excess minerals putting cannons on the cliff south of my base, which helped once the CPU started building there, plus they helped with Wraiths. We didn't need the help of the Beasts at all. By the time we were able to beat Purple and White, Brown wasn't an issue or threat at all.
Overall, it's a pretty basic map and unspectacular in the grand scheme of things, but that's okay - it's a first map. Most here have been playing and/or creating for years, so there is much to be learned from experience.