I know this is a big one but here we go..
Would be awesome if there could be other things to do in the game besides working at the facility. Perhaps have your own flat you can travel to after / before work, sleep, go to a bar and pick people up etc. perhaps even including some multiplayer features with that.
This would SIGNIFICANTLY alter the game and ultimately depends on the developer's vision whether or not to implement but I find it worthy of suggestion :)
Perhaps an overarching light storyline of sorts would be awesome as well.
Customer support service by UserEcho