Just purchased. I like the style and story a lot so far; the setting seems inspired by Battle Angel Alita, and the game definitely reminds me of Metroid. The game mechanics are mostly intuitive and easy to figure out, but the tutorial is recommended since it fills in some minor gaps. HOWEVER, be aware that a necessary folder "save" may not be properly created when the game installs. You'll end up playing for 15-20-60 minutes, supposedly saving your progress along the way, come back to continue your game, but... nothing, no saved games. Previous play: wasted. If this occurs, go to your install location, e.g. ".\GOGGames\Ghost 1.0" and manual create a new "save" folder. Now it should properly save your games. Not sure how this got past QA; it's a pretty significant issue.
