Alpha Project Gre is a resource pack, currently, for 1.13, that changed the whole world (not really...)
This resource pack is basically just default resource pack with some animations and new designs for few items or blocks. The good example of it is Block of Redstone and Barrier, Block of Redstone has a new animation similar to Sea Lantern from Vanilla Minecraft and Barrier has a unique new design, it now looks like a block but it's not 3D.
