Purchased this game today. Downloaded it. Went to play it and all that opened was a vibrating pink screen which can only be removed by shutting down your computer.
Any advice on how I might fix this situation would be greatly appreciated. (I'm old, and relatively new to Mac games).

... to a modern classic. And it's not just a tired rehash of what you've experienced before. This is a very different place, story and perspective. Recommended to the highest degree.