Thank you for the feedback! :)
I'm not sure what causes the crackling, but this is an issue in the browser. The executables don't have it. The crackling comes with the ambience, so if you mute it, it should probably be ok. I wrote that in the description, but personally i never read descriptions :D
I'm not sure i understand the last point. You do have to make a choices at some point - for example what to prioritize in unlocking. Some people go for the laste, i personally like the speed, but the drill is also very useful. You won't have enough resources to get them all. If you got the last drill, you can finish the game by digging down as far as possible (this is not communicated well though).
I understand the annoying fullscreen thing - i changed it to use another key than ESC. Other than that, there is this little button in the lower right corner for fullscreen, this also works.