How to Kill the Boss in "Motherload"by Timothy Baron ; Updated September 22, 2017
"Motherload" is a free online Flash game. Players control a mining vessel as it drills into the depths of Mars. Along the way, they collect valuable metals, which they can sell for better equipment and supplies. Although it's a mining game, "Motherload" also features a battle at the end of the game. Because your ship does not have guns or other weaponry, you have to use your mining equipment in creative ways to hurt the demonic boss.
Go to the item shop. It's on the surface on the far-right side of the screen.
Purchase at least 10 plastic explosives. The more you buy, the better your odds of beating the boss.
Drill to the depth of 66,666 feet. You'll find the boss here.
Drive to the feet of the demon and press "C" on your keyboard to lay a plastic explosive. When it goes off, it will hurt the boss. After 10 hits, the boss will die.
You should buy hull repair nanobots, too, before battling the boss. If you get damaged by one of the demon's attacks, you can press "R" to repair your hull. Although the demon's attacks are slow enough to dodge, if one hits you it will cause a considerable amount of damage.
- link GameFAQs: MotherLoad