A good arcade/platformer, collect crystals
6 worlds, each with 7 one-screen levels. After every world the program saves your game.
In "Crystal", you have to collect all the crystals in the level before time runs out. By going through 7 levels, avoiding enemies, dodging spikes, jumping on platforms and springing into action, collect all the crystals to get one step closer on getting the rare crystal.
SHIFT - Jump
LEFT - Moves to the left
RIGHT - Moves to the right
UP - Climb up the ladder
DOWN - Climb down the ladder