Java Edition Alpha v1.2.1

Alpha v1.2.1 was a version of Alpha released on November 5, 2010, to fix bugs. Although the launcher claims to have this version available, the version listed is just a duplicate of Alpha v1.2.1_01.

Changes

 * Mob spawning reverted to old code.
 * Leaves particle colors now reflect the biome instead of having the grayscale texture.

Fixes

 * Signs on the sides of cacti no longer crash the game.
 * Optimized CPU usage for mob spawning.
 * Music now plays in multiplayer.

Trivia
This is the newest version that is lost as of March 7, 2019. Every version after this is either in the launcher or achieved elsewhere.