Dungeon TD reverse

My first-ever project!

The rules are simple: Every 30 seconds, you have to pay 1 coin for workers salary. You have 4 diggers, which are really lazy.. By using Arrow keys on keyboard, you can send them digging ores and hunt the enemies. You can also return them to base to heal using same key. The upgrades are in the bottom left corner. Each costs 5 coins and you can upgrade: worker HP, Speed and their damage by improving their tools!