Minecraft Alpha v1.0.2 was a version of Minecraft Alpha released on July 6th, 2010. This version is severly overlooked and not much is known about this version and is considered a piece of Minecraft lost media. The version's counterparts: Minecraft Alpha v1.0.2_01 and Alpha v1.0.2_02 have fortunately been found and retrieved and have information on the versions. Alpha v1.0.2_01 made changes to redstone (Minecraft "electricity") as redstone dust can no longer break when a player or an entity steps on it, it also emits dust particles, partially obscuring the object itself and no longer connects through blocks diagonally. Alpha v1.0.2_02, on the other hand, made changes to water as water has its level data value (the different types of blocks, items and features) directly set to 0 only if there is a block or another body of water underneath.
Minecraft Alpha v1.0.2_01 image:
Minecraft Alpha v1.0.2 extra info: