"You wake up in a cave. Your power indicator blinks red rapidly. Panic.

"Luckily, this cave is littered with energy-laden crystals which you can consume to replenish your power source. Find your way to the surface, and don't run yourself out of power!"

Some early concept and design work:

Rough sprites:

In-game movement:

You play as an android with a gun arm. Be careful with using your gun though, it uses a lot of power!