Little Miner

Controls: Use the A and D keys to move left and right, use the space bar to jump. The S key is used to mine down, and the W key to mine up.

Gem info: Try to get the BLUE gems not the RED ones. You can go to a second screen by moving to the right, that is where you can deposit your gems to turn them into money, it will subtract the number of red gems from the number of blue gems.

Ways to use/lose gems: Your gems can be lost by touching a thief, a boulder, a stalactite, poison gas, or by falling in a lava pit. You can also use money (deposited gems) to buy items from the shop (click the thing at the top of the screen to open the shop, and click anywhere besides the shop to close it), the bottom three are upgrades (permanent) while the top three wear off after a bit.