I am found in many lands, from the mountains to the sands. I bring you joy and sometimes pain, and can make you play again. What am I?
A long shot:
I am found in many lands, from the mountains to the sands.
Shells are notoriously distributed not only to the shores but also to mountains due to how earth progressed. Ross can provide further info.
I bring you joy
They are used in decoration, and also in a romantic "listen the sea of sound in them" fashion
and sometimes pain
a shotgun shell, an artillery shell can do that
and can make you play again
Well until now, the "knowledge" tag is not used. Since "play" is intrisically linked with "game", I'm sure anyone can think of some game with some shell in it. Any FPS with shotguns will do. I opt for Shelly de Killer from the Ace Attorney series.
My best guess is
Salt brings joy as a common seasoning with a savory quality.
Pain could mean someone who is salty. Eating salt by itself is also painful, lol. Even food that is too salty is no good.
Salt can make you play again because it is a common source of the electrolyte sodium(think Gatorade etc.) - electrolytes aid in effective hydration.