i think i took a break at some stage... it also included a few minutes where I was eating. I wasn't really trying to go fast. Think I just working out best placements. You get blueprints based on score so if you can boost the tiles up to point you get at least 5 points per tile at the end, it speeds up the game.
Since the end of game is reached by placing the last monument, it likely has a score you need to have to get it - I haven't been taking that much notice. So faster you can reach that score, the quicker game is.
I don't know what fastest would be. I expect a speedrun at some stage - TAS would be interesting as it would make placing tiles perfectly less time consuming... not that this game as punishing in tile placement as Dorf. Its more relaxed. In dorf, every edge can be different on a tile, whereas in this game, if a tile has water and trees, all edges of that tile do as well. Easier to get high points.
Another difference between this and dorf is this has an actual end. Dorf ends when you run out of tiles. This does too but it also ends with placing all the Blueprints.