This pack is not at all a complete texture overhall, it is instead just an improvement to many of Minecraft's disliked and bland textures
To start, bricks, and brick like blocks, and ore have texture variations based off the default textures. In Addition, prismarine textures have been given a purpur/copper like design to make them fit in more, quarts blocks have a more tradition stone brick design and better shading, and even smooth stone has better border shading to match smooth stone slabs better. Sand is also been given a soul sand like pattern.
Another main focus of this pack is removing the dark/thick outer border found on many polished blocks. Adding borderless glass was one of the main purposes for creating this pack Polished stone type blocks, iron, lapis, shroomlights, and cut sandstone no longer have the outer borders, and with OptiFine, all smooth/polished stone type blocks with have connected textures.
Many tools also have had texture tweaks aswell. No two ore tools have the same exact design, as they have all been tweaked slightly to more fit their material and tier. For example, stone tools are smaller and more rigid, whereas iron tools are thinner and longer. Higher tier tools like diamond and netherite even feature some lower tier material textures for design.
Other than these main focuses, multiple smaller and more subtle changes include lower side/full side covered grass like blocks (depending on the pack), rounded tops of trees to more accurately represent tree rings, arrows on the sides of droppers, dispensers, and observers to indicate the output. Also a numbered hotbar, new crosshair, rounded spyglass lenses, and a few more subtle changes.
Many new items, some stone brick variation, and a few mob changes were made. And recently, a few item names have been slightly altered for consistency and ease of search.
One of the latest features Is a new dark mode for in-game HUDs and the UIs. Item slots are also now semi-transparent, so you can see through empty slots to look out for danger. Smoker / Blast Furnace GUIs also have indicators to show what kind of items they smelt, and crafting tables have the 3x3 crafting grid design from the top of a crafting table in the GUI.
There are two packs: a base pack with no outer borders and full side covered grasses, and an OptiFine tweaked pack with borders and lowered side grass (designed to be used with OptiFine "Better Grass" and "Connected Textures" settings on). Both contain texture variation and the ctm files however.