I've not bought the GOG version, but I have both the first Dungeon Keeper and Dungeon Keeper 2 installed on an older, Win98 computer. I bought the games about ten years ago, and I have played them a lot, and downloaded lots of player-made maps. In general I do not like rts games, although bought Seven Kingdoms from GOG out of curiosity about the game mechanics. I prefer turn-based strategy because it allows for much greater depth. Why then do I like these two games? This seems to be largely down to the fun setting. They seem to have been the first games designed as a sort of inversion of the dungeon crawling type of game, playing the dungeon master as opposed to the hero, and still even now they seem to be the best examples of that inversion. The fun setting certainly helps one to tolerate and even be amused at the idiotic behaviour of the creatures defending your dungeon. This contrasted with the idiotic behaviour of one's troops when playing Command & Conquer, which could be very tiresome. I think that there is also less annoyance in this regard in the DK games because most of the time you do not try to directly command creatures that are supposed to be serving you. In this respect DK 1&2 are like the later game Majesty which is another rts game I liked. Unlike Majesty, you can directly control creatures, at least in so far as you can re-locate them to another part of the dungeon, and you can slap your minions to make them work faster. On the other hand, in Majesty you have complete control of recruitment, while in DK 1 &2 only your minions, your basic workforce for digging tunnels and transporting gold and items, can be directly recruited, the other creatures are randomly spawned, although you can be sure of recruiting them when they spawn by controlling the gate, and your room layouts affect what creatures you can recruit. DK 2 is a more polished game than DK 1 and there was one serious flaw in the game mechanics of DK 1 which was corrected in DK 2. DK 2 did also add a number of game play elements which enhance gameplay. Nevertheless DK 1 manages to be just as much fun. Both games come with very long single player campaigns, and there are a number of secret levels to be unlocked while playing some other level. Some levels are quite hard, and I've sometimes peeped at walkthroughs you can find on the Internet to help me out. But I find almost all the levels I have completed have been endlessly replayable. On re-installing one of the games, I find I have to go through all the levels again that I have played before, no skipping, but I never resent this, even though half the campaign is about teaching the basics of the game.