I hate whoever it was that mentioned DK was free on GOG. I've wasted the whole weekend playing it. I'd forgotten just how addictive it is!
Sadly I'm now stuck at a level where the enemy keeper rushes you within about 5 mins of starting. No matter what I build or do it isn't enough, I have stronger creatures, he has strength in numbers.
First time so far I had to listen to the "your dungeon heart is under attack" :(