SteamWorld Build

You earn money mainly from taxes, you can see your balance under your funds at the top of your screen. Each time a cycle ends, your balance is added at your funds. In the fast setting (activated by the button), each cycle takes 7 seconds.

Now, you could wait patiently for hours or... you can create a lot of paintings. In the train station, you can trade your goods into other ones, money included, paintings are the most profitable good, selling at 1600 each. You can even sell 4 other products that you are comfortable with in order to get rich even quicker. If you prioritize the most expensive goods, you will be at 1.5 million in less than an hour

2nd method: If you still have a playthrough to do, at the start, build the maximum of lumberjacks you can build and fill your trades with only packs of 25 wood logs for 2500 money, it doesn't seem a lot but you will get to 1.5m without even thinking about it before the rocket launch

you need to have 1.5 mil cash on you at once. if you set up a world with a good income you can leave it on overnight and itll rack up. my world had an income of 617 and overnight it hit the amount needed for the achievement before my xbox went to sleep