How far are you?

I'm working on the first mission of Secret Mine. I'm 100% finished with Gloomy Manor, I just need to collect some missing Gems in Haunted Towers and Old Clockworks and I'll be completely done with them as well. I think I need to get three stars in a few missions Old Clockworks though. I'm trying to figure out what to do in Secret Mine at the moment, very tricky for me.