Nice!
It was very interesting to listen to this piece, I enjoyed the different parts of it and the way the song was in a constant evolution.
The first part with the acoustic guitar reminded me of the music from those games I used to play when I was younger in which you have to build a city during the Antiquity and stuff, like Civilization as Tadashiini said. I really like it, it would really sound perfect for one of those game. By the way, I assume you didn't play the guitar and you programmed it? If it's the case, it sounds absolutely beautiful and realistic, and I must say the other instruments you used sounded brilliant.
Then comes another part at 1:43. This one sounded epic! The chord progression was pretty simple but the way you arranged it with the low octave played by the piano, the strings and the piano melody made it sound just epic. Though I would have enjoyed a bit more rhythm on it, you know to make it sound more lively.
Another part at 2:17 starts, I think it was my favourite. Loved that bluesy lick played by the flute, I think. I must say I didn't expect that coming but it created a nice element of surprise. And the guitar behind it was rocking, acoustic guitar + rock-ish riff = win. The repeat myself, this part deserved more percussion too but maybe that's my metal guy influences that want that :).
Overall I enjoyed this one very much. Though there were a few thing that I would have expected such as more present drums (percussion) but that's a matter of taste so I won't penalize you for that. Great job on this, keep going :). And check my songs if you have some time ;)
Gave it a 5.