DigDig was a game I made to be simple and fun with a lot of polish. I kept the design very focused on just a few mechanics and spent the rest of the time making everything as clean as possible.

The basic elements are the green crystals that grant you extra score, blue crystals that increase your score multiplier, the gas cans to refuel and keep moving, and the wrenches to repair damage taken from drilling through lava. While your craft is damaged you will leak fuel and become empty much faster if not repaired, but lava is easy to move through offering short-term gain for a long-term consequence if not dealt with.

Perlin noise was utilized in layers to determine the hardness of each tile, the harder the tile the longer it takes to drill through. The player must decide where to drill to ensure they can continue to refuel and grab points without running empty. The player may not dig up, ensuring the players must eventually travel further down where harder rock becomes more frequent.

The game and it's reviews can be found on it's Ludum Dare Page:
https://ldjam.com/events/ludum-dare/48/digdig/comments