I discovered today that my most played game on Steam is Astronner with about 500 hours, and my second most played is Surviving Mars with about 500 hours.
In September the game is being vastly reworked. Lots of the mechanics are being changed. The skill trees are being completely re-conceived. This will likely be it's final form.
If you get it now and finish a play through by then, sure it'll be worth it.