Thanks a lot!
2. Indeed, there's no sound at all. In a next update maybe.
4. MINE is the actual minerals below your sentry. The blue thingies. It'll decrease as soon as the robots steal some. METAL is what you obtain once you kill a robot. It helps you upgrading your sentry.
6. No, probably a bug at some points. As it's an unfinished game, I didn't make it perfect.
7. yes :D
You pointed out some good points, I'll fix them, thanks again!