It's Space Fortress 2.
http://www.pixelships.com/sfort2/

Googling for "ancient dos games" brings us to this site: http://www.pixelships.com/adg/
where Space Fortress 2 is still on the front page as "Filler #16 - Space Fortress 2 Released May 5th, 2012".

Since I do not really know the game and merely solve it by the obvious hint, someone please take my turn and post the next pic. Thanks.

Ok, I'll try to post "not-that-difficult-to-guess-but-fun-nevertheless-riddle". It's a game I would absolutely love to see here. I've even personally put it on a wishlist.

I WAS trying to post something not THAT obscure... it seems I failed. Perhaps next screen will be easier (the menu is not hidden so the game is easier to identify)

Alright then, here is a relatively recent title

edit: OH GOD NVM
Wrong era!

For some reason my brain screamed Hears of Iron 3. No idea why.

e: probably because it's the only Paradox game I've ever played.

That would be Commander: Conquest of the Americas

Nice hint in the name of the file ;)

I usually try to hide some minor hint in the file name when I can come up with one.
Anyway, your turn!

The ship from your post was sailing to Amsterdam and after reaching it...

High Seas Trader

Of course! Your turn

Well, what can you tell me about this one?

looks like north & south.