I gave it a try the other day and really enjoyed it! Really nice cartoon art style / setting. The above-ground portion of the game feels like a solid clone of the Anno series games. Then below ground adds a fun twist of exploration / resource gathering into the mix.
Really looking forward to when it releases now!
It does seem to exist on steam. I haven’t pulled the trigger, but they made a different very different looking version, and if you dig down to the description it says it includes “motherload goldium edition”. I have it on my wishlist to buy if it’s ever discounted a bit in a steam sale, but the newer game doesn’t appeal to me enough to spend $15.