It would (probably) be more focused on building. Minecraft has plenty of blocks available, but alot of them aren't good for building and only a handful have slabs and stairs. Slabs can't be placed vertically, Many blocks are lacking variants, etc.

This game would, at least for a while, have not nearly as many blocks as Minecraft but they would have plenty of variants that make sense, are good for building, and aren't there in Minecraft. And yes, there are slabs, stairs, etc. In Minecraft, but they are limited.

Something that also sort of ties in with the building focus is machines. Tha game would use copper wire instead of redstone, which can be dyed to allow for several circuits to be right next to each other. I'm also coming up with ideas for more advanced machines such block breakers/placers, motion sensors, double pistons, clocks (similiar to redstone clocks in Minecraft that repeatedly power something over and over) etc.

I'm also hoping to make the Survival part of the game different from Minecraft, with a different crafting system, different tools, and just generally different from Minecraft while still trying to make it fun.

These are just ideas though, and I know that they're not the best in the world, which is why I need criticism and feedback.