Java Edition Classic 0.0.13a/Development

Several unreleased development versions of the game labelled 0.0.13a were developed on May 21st. They show in-development features later included in 0.0.13a and later releases. The huge world size features showcased in these versions would not be publically available until 0.0.14a.

World size test 1 (May 21, 2009)
Download client, Download .json
 * Additions
 * Added a thin black block selection outline.
 * Pressing Esc now opens the pause menu, with options to return to game, generate a new level and save/load level, the last of which doesn't do anything.
 * Changes
 * Game ratio is now 854×480, not 640×480.
 * The block being used is once again shown in the top right corner
 * Made swimming and sinking faster than before.
 * Swimming in lava is now slower than in water, no longer the same speed.
 * Holding the key no longer allows for autojumping.
 * Jump height reduced back to just over 1 block instead of just over 1.5 blocks.
 * This is the earliest version in the launcher where holding down R no longer causes the player to cycle between different locations - holding the key now has the same effect as simply pressing it.
 * Lava is no longer transparent and has a thick, red mist when underneath it.
 * Changed the texture of saplings from Oak Sapling JE1.png to Oak Sapling JE2.png.
 * The generated world is now completely flat. When generating a new level from the pause menu, the world will be of a long shape (512x64x32), but still flat. It is worth noting that caves can still generate in these worlds.
 * Trivia
 * This is the version available in the launcher, added to it among several other versions on August 6, 2013.

World size test 2 (May 21, 2009)

 * Changes
 * The world is now 1024x64x64 instead of 512x64x32 in size, and generates actual terrain.
 * If water generates next to lava on world generation, it will now produce stone.
 * Reference
 * Minecraft IRC logs, May 21, 2009
 * "(10:48:56) Notch_: and I just tried making a 1024x64x64 map. It's nuts [...] (10:49:06) Notch_: it's basically a looong gauntlet of hills and lakes"
 * Trivia
 * It is very likely this version has the new level generation screen, however this is not confirmed.

Huge levels (May 21, 2009)
YouTube video (reupload)
 * Changes
 * The world size is now 512x64x512.
 * Terrain has been updated to the 0.0.13a_03 format.
 * Dirt layer is now more uniform.
 * There is always a single block of dirt after grass and before stone.
 * Surface lava lakes still possible, as seen in the video.
 * The world generation screen has been changed.
 * The dirt background is now darker.
 * Added a progress bar below the progress text.