This achievement is misleading, because it does not actually track time spent playing. It only tracks time spent running each simulation, which take 10-15 seconds apiece, usually.
If you figure everything out on your own, then this, and the 1 hour achievement, likely won't be an issue.
But if you follow a Level Guide, such as the one in the video below, you may finish the game in under an hour, leaving two hours of grinding necessary.
There are two options for grinding time out.
The Level 30 Solution in the video runs for 18 seconds, which is the longest run-time. You can repeatedly replay level 30 over and over until the time adds up.
You can also simply start with Level 1 and re-run all of the levels over and over, only needing to Press A repeatedly to advance to the next one when the Simulation completes. However, my solutions do have an occasional misstep with hitting a pedestrian, inwhichcase you'll need to pay attention to reset the level.
If you were able to run all 30 levels without fail, you could in theory run a turbo controller with the A button turboing and just check back every once in a while, but it runs into the same issue. If a level fails, the game will stop until you press the X button, so it COULD work if you check in on it, and it may still be better than mashing the A button repeatedly, but unfortunately there's no great way to grind time short of solving the puzzles yourself.
The Level Guides start at (18:47)
The Method for Grinding Time starts at (52:24) and uses the setup from Level 30's solution at (50:39)