Ah well, a 2/5 against you with Mountebank on the board is always going to hurt.
Personally though, I'd have opened differently on seeing your opponent have a $2 opening hand, as with Mountebank around the chances of Fools Gold colliding are much reduced. Likewise, Ghost Ship may have been a poor attack card of choice against a Fools Gold player, as they only need 3 FGs to hit province, and can stack back FGs on thr turns when they don't have that, increasing the odds for that turn.
My own choice would have been to answer Fool's Gold with Ambassador, and Mountebank with Ambassador.
A double Ambassador opening would have passed curses and coppers back to your opponent, as well as keeping his FGs apart. After that, Money all the way to Provinces!
If I may, I'd observe that you were playing only your own half of the table, and disregarding what happened on the other side. Fool's Gold / Loan might be reasonably quick in a solo game, but in the face of another player, with the cards on table, Ambassador was the crux card, and Fool's Gold a weak point.
Likewise, while City, Apprentice, Black Market and Ghost Ship are all excellent cards, and even Develop can be useful, I don't think they fitted your strategy, the game situation or your deck at the time you bought them.
