ASC is a free, turn based strategy game in the tradition of Battle Isle. Its features both single player gameplay against an AI as well as extensive Play-By-Mail multiplayer functionality.
This review isn't exactly accurate as I haven't played it in a few years. But it was a great game. Learning what you are looking at on the right-side of the screen and how to use what you see can be a bit tough. But the game played well, I loved the scenarios, and the creator was active in helping players at the time. I recently re-installed the game and will play it again soon.