The first mission worked. But when the 2nd mission starts, it freezes again. I restarted steam + game and started 2nd mission. The game's cursor is visible, the voice output is played but the screen remains where it was.
When the mission is running and the graphics output freezes, I have to press ESC (pause it) and then ALT-TAB and select the Anomaly2 process to have the graphics back.
The 4th mission is always freezing. It seems like that it happens right before the "Press space bar to continue" message on bottom of screen appears.