A tip for when this is the badge of the day (learned the hard way):
-You only earn revenue when you have areas conquered, you can't just buy a bunch of marketers and revenue upgrades and let it sit there
-Buy ALL employees in every department BEFORE upgrading how many you can have, they will cost the upgrade price even if you haven't maxed yet.
-Don't buy employee upgrades until you're at a comfortable revenue, you will bankrupt very quickly
Hope this helps you get the badge and you avoid the same mistakes I made, several times lol
Reading the comments on this game I realized people give up too easily. If the game is not completely easy they hate it. This game is very fun and so easy to get the medium badge you just need to upgrade. I did the final boss in like 15 seconds after entering that room maxed out. Quit complaining about the difficulty and just enjoy the simplicity and art the developer created for you.
What an incredible game. I got all 3 badges in 45 minutes and didn't even need to use a guide of any sort. Pretty amount of challenge to where you can easily solve the level but feel smart doing so. Hard badge is just beating all 40 levels and they are all equally fun. 10/10