Good introduction to the Hidden Gems episodes. My only downside is that I think you've showcased too many levels at once, you should save some for later instalments of Hidden Gems, because you want these levels to get attention, and there's about 1 in 30 chance of someone picking the same level. Whereas 5-8 levels maybe, will expand and there's more of a chance of getting played. Otherwise, very nice.
The idea of level supermarketing is old, but the way you presented them in a miners theme was excellent. I'm more impressed with the level than those showcased, but that's just ironie for you.