Alone it can get boring, as after all, the game doesn't guide you through anything, so it all depends on you, but with friends and wanting to try and do something, you can end up spending tens of hours on it easily. I've been playing FTB (feed the beast, a huge pack of mods), which has given the game hundreds times more content, with lots of more complex stuff, and using the mindcrack pack, which is the hardest one, so you always end up doing a billion other things for hours just in order to get one "simple" thing done. Say, building a quarry, which is a machine that digs a big hole for you (which needs a lot of set up with engines, which need their own fuel etc too, and stuff to sort/store all the stuff dug up automatically), lead me off to piping oil, refining it, which lead to searching for deserts to get cacti to make waterproofing for pipes, but not finding any so going with bees wax to do so, leading to raising bees to get their wax and all sorts of other stuff like that. And that's just for the fuel for the engines, let alone the stuff needed to make the stuff neded to make the quarry itself haha. It just doesn't end, and no matter how long I play, there's always TONS of stuff that I have no clue about. Very easy to lose huge amounts of time with it lol