Went through and checked, there are 5 cards in the set that care about/reference mines. Look for about double that (and a mine intro deck) in Dark Omens.
They may but it wouldn't fit in the set. If you read the background, mana has been very weak for a long time (which is why theset is a bit underpowered/overcosted). Also unlike StS, this can hit lands.
At least with what I have seen, there aren't a lot of cards that care about mines, and there aren't any in common. I really really suggest that this becomes way better. It's nice that it can tap for 2 in one turn, but it's horrible that it can't anytime later. Even if mine were a strong theme (the cards aren't that strong), it'd be a bad choice to have a bad common that helps good uncommons or rares. It's much more reasonable to have usable commons that get better by good but not broken uncommons or rares. Given that you need to play with these mines, that the effects still cost a lot, etc. I don't see how you think this would be too good. Compare to the Urzatron, for example, or Sift Through Sands, or Dark Supplicant.
changed ETBs tapped to ETBs with a counter.
There are one or two ways to add counters in this set and more in Dark Omens. Plus, there are uses for Mines in both sets. I am working on an 'Intro Pack' to post on a details page that will show why this exists and how it works.
One counter is I feel sufficient as it allows you to tap this for the turn you play it.
I don't know what it was like before but I'm definitely starting to like it now. I think it will always look odd if you see it in isolation and it can't tap for mana at all. But having skimmed the rest of the set, I can see why it exists. It's definitely normally worse than basic, but may be useful if you have good ways of getting mine counters on.
A compromise might be to start it off untapped or with one counter on, and/or make it tapped for colored (although I like the flavour of tapping for colourless) or maybe for 2 (although that's risky). Then you can see that it's worse than a basic land normally, but you can see what you might do with it if you can get some mine counters on.
Hafta add the flavour text. Divide and conquer in that, if they don't work together then they can't block you, so opponent either double blocks or doesn't at all. May need a new name though.
The standard would actually be "as long as you control no colored nonblack permanents". But that's ugly. Use "as long as you control only black or colorless permanents", that's also standard.
Went through and checked, there are 5 cards in the set that care about/reference mines. Look for about double that (and a mine intro deck) in Dark Omens.
Oh, forgive me. I totally didn't read "or land". Never mind, then.
OK big change to this to differetiate it from StS. Wording is very messy though.
changed cost to
as at 
it was strictly better than Fireball.
Looking forward to those interactions, then. :)
Template issue: it should say "...enters with a mining counter on it." The last ability should be "Remove a mining counter from ~:..."
this is as good as this is going to get. It will make more sense once all of the Dark Omens cards are up.
They may but it wouldn't fit in the set. If you read the background, mana has been very weak for a long time (which is why theset is a bit underpowered/overcosted). Also unlike StS, this can hit lands.
At least with what I have seen, there aren't a lot of cards that care about mines, and there aren't any in common. I really really suggest that this becomes way better. It's nice that it can tap for 2 in one turn, but it's horrible that it can't anytime later. Even if mine were a strong theme (the cards aren't that strong), it'd be a bad choice to have a bad common that helps good uncommons or rares. It's much more reasonable to have usable commons that get better by good but not broken uncommons or rares. Given that you need to play with these mines, that the effects still cost a lot, etc. I don't see how you think this would be too good. Compare to the Urzatron, for example, or Sift Through Sands, or Dark Supplicant.
I think everyone prefers Smash to Smithereens. Try
for the cost and instant speed. :P
changed ETBs tapped to ETBs with a counter. There are one or two ways to add counters in this set and more in Dark Omens. Plus, there are uses for Mines in both sets. I am working on an 'Intro Pack' to post on a details page that will show why this exists and how it works.
One counter is I feel sufficient as it allows you to tap this for
the turn you play it.
I don't know what it was like before but I'm definitely starting to like it now. I think it will always look odd if you see it in isolation and it can't tap for mana at all. But having skimmed the rest of the set, I can see why it exists. It's definitely normally worse than basic, but may be useful if you have good ways of getting mine counters on.
A compromise might be to start it off untapped or with one counter on, and/or make it tapped for colored (although I like the flavour of tapping for colourless) or maybe for 2 (although that's risky). Then you can see that it's worse than a basic land normally, but you can see what you might do with it if you can get some mine counters on.
How about removing the "doesn't untap" clause? Does it have to be that bad, and worse than a basic land?
Made that change.
Hafta add the flavour text. Divide and conquer in that, if they don't work together then they can't block you, so opponent either double blocks or doesn't at all. May need a new name though.
The standard would actually be "as long as you control no colored nonblack permanents". But that's ugly. Use "as long as you control only black or colorless permanents", that's also standard.