Build: Alpha 4
OS: Windows 7
Core i7 2.50GHz; 16gb RAM
Graphics: Intel HD Graphics 3000
After a random period of time, the screen refresh stops responding, requiring a restart of the game. You can occasionally get some areas of the screen to refresh from mouse movements, but all other means of working in the UI stops responding (ie, hitting ESC to dismiss menus, etc)
Initially this was not too much of an issue. However, the most recent occasion appears to have corrupted the savegame. After restarting, the option to load any of my previous saves was not available. For all intents and purposes, it presented as though I had never started a game at all.
One possible contributing factor is when the screen refresh bug happened the last time, I attempted to save the game (using the mouse to refresh the parts of the screen and reveal the save button).