Being still under development, this is brimming with potential and system depth I haven't seen in even AAA games.  That said, the whole game is just...slow.  I know that's kind of the point - it's a simulator game aiming for a more "realistic" progression speed - but that means that after some 40 hours in-game you're still what feels like a long way from what you can see on the horizon.  There's also a limit to how much stronger you can get and therefore what enemies you can take on, which is also realism that I can accept as a point...but still dampens the experience for some players.