How to play Boulder Dash demo? Can't find any diamonds. I just die.

[GradualGames]

For the life of me I can't figure out how to play Boulder Dash. All that happens is boulders fall on my head and die. Sometimes they fall on the ground and suddenly 9 diamonds appear. I know I'm supposed to get those diamonds, but I only see them after I die.

 

What am I missing? Haha

Edited August 21, 2018 by GradualGames