Do you want your luck to increase? Or maybe you want to mine deeper? Or you just simply want to craft more blocks and items? You need to upgrade your skills. To upgrade your skills you need skill points. These can be obtained by completing achievements. You can find the achievements on Game Center on iOS.
Here's a complete list of all the skills, and what they are for.
•Agility - Move/climb/swim faster, Jump higher, Reduce physical damage, and Increase stealth cloak duration
•Automata - Craft turrets, robot pets/helpers, and Butler Bots.
•Building - Craft better items. Place blocks further away.
•Engineering - Craft better items Use advanced weaponry and devices Use steam more efficiently
•Luck - Find better and more quantity of treasure in crates/chests/etc.
•Mining - Mine faster, Mine deeper (L2 - L4), Mine more kinds of objects
•Perception - See teleporters on map at L2, explored areas at L3, zoom out at L4, increase zoom L5+
•Stamina - Start with more max health, add more accessory slots.
•Survival - Reduce acid/fire damage, craft jerky (L2) and power jerky (L3).
Note: Without premium you can only upgrade your skills to 3
To upgrade your skills you need to complete a achivement.Then you tap your players head in the upper left corner (ipad only) and hit the plus sign. Then you choose the skill, and it will be increased by one.