Okay I'd like to point out that the stone age was about 3.4 millions years long and that by the end of it while humans weren't quite masters of all they surveyed we were well on the way.
I'm not going to try and say exactly how the world would be different but I'm going to point out some guide posts for you to look at while you work out the details you want. Machu Pichu is one of the most sophisticated cities ever built, ever not just using stone age technology, in some ways it is superior to modern cities, especially in it's management of water and its ability to withstand earthquakes and landslides. There are rice terraces in Myanmar that are earth and stone over 500 years old and built without metal tools. The pyramids were built with metal tools using stone age techniques the only difference would be construction time, with Egyptian monuments that's true generally, none of their work can't be done with stone tools. Construction endpoints cities and castles yes, high rises not so much, anything you can build with bricks and mortar is a goer.
Quality of life is generally quite high by the end of the Neolithic but the margin of survival isn't awesome, food surpluses from farming are small most places but you can support a priesthood and artisan makers.
Weaponry
Studies have shown that a flint head, and a steel broadhead do about the same amount of damage going in (assuming target isn't wearing metal armour) and the former tends to leave more material in the wound than the latter but requires more time and skill to create. Swords not so much, clubs of every kind and material oh yes, I'd look at what the Aztec and Maya did with stone age weaponry for references on what's possible.
The biggest difference is probably going to be forest cover, the temperate climax forests of Europe, weren't really heavily impacted by humans cutting for farming until the Iron Age, stone and bronze tools weren't up to the task of felling those trees and slash and burn doesn't work well in the wet European climate. The land that was cleared in Stone Age Europe was mostly high up or otherwise presented poor conditions for forest cover. That's going to impact population because there will be tens of thousands fewer acres under the plow worldwide.
There are a number of animals that I wouldn't care to hunt with stone age weapons, like the cavebear but none that you couldn't hunt, conceivably even to extinction. There are creatures that will probably go extinct regardless like the mammoth and other cold adapted Ice Age species.
Travel is interesting, the skin-boat or coracle was invented in the stone age and still in use in the 1900s but they weren't a long range mode of transport, there's nothing to stop you building a Viking Longboat or even a wood hulled clipper-frigate with stone tools, the clipper-frigate does ideally need metal bolts though you could do it with wood if you were willing to accept a lower performance. The question is are they worth building under those conditions and can you actually fell the wood you need for them, the wood is a bit of sticking point but you could use smaller trees and laminate but the work required to built something seaworthy, in the sense of "there's an ocean, we have no idea how big it is, let's go!", I don't know if that could be justified when the margin of survival is lowered by that much.
I think that's the broad strokes, let me know if there's something in particular you want me to talk about.
