Funny and amusing situations...

hunter98, and on which map is the game being played? Judging by the mini-map, it's not a random map, but a custom one? Well, there might be various factors that prolong the game: for example, some kind of guardian of a passage in a key location, requiring you to bring a hundred creatures, and you can only get them in castles by accumulating them. Or, as happened to me recently: the map prohibits the use of the Town Portal, and you have to run after the enemies back and forth until you deal with them all...
Although, of course, it could also be that these guys are just slow... From the video, which only shows the end of the game, I can't tell.