So I purchased the game some time ago, It was 16.05.2013, I guess. And it means that I couldn’t play it on steam at that time, I just downloaded it an played it. I wanted to ask if I give the information about my order, can I get the game on my steam account? I really loved the game and since it is possible to download mods from steam workshop now, I really want to replay it!
Yes, you can.
You only need to redeem the Steam Key.
Where can I find the steam key? From the messages I got from Greenheart in my hotmail?
the order number in the message?
I think so.
Sorry doesn’t work, but I noticed a sentence in the message I got:
“Steam keys
At the moment our game is not available on Steam. If you would like to see the game on Steam please cast your vote.
If and when the the game becomes available on Steam we aim to provide you with a free Steam key.”
OK, thank you 
No prob 
Hey @cakimenmen
Did you purchase from the Windows 8 Store or our Website?
Please refer to this thread on our forum re Steam Keys;
http://forum.greenheartgames.com/t/faq-game-dev-tycoon-steam-keys/6728
Please note that Windows 8 store customers must claim their Steam key from inside the game. Please see the above forum post for more info.