The game you're looking for
is called
Kingdom, but it's not the Kingdom that Megaten referenced. Here's a screenshot that should bring back a rush of nostalgia:
It was part of the GW-BASIC pack, which you can download
right here.
The game files are in the .bas format, so you'll need an extra piece of software to run them. I used
Qbasic and it worked like a charm.
Lemme know if you need any further help.