I've reskinned races entirely in my campaign, to swap all non-human races for alternate human types. Yes, all are human, with the same speed (30'). They are
- basic humans (that have a specific race name) that are the humans from the PHB, they are the settlers that recently (less than 1000 years) came to the Vale, imposing their ways to the other more savage races
- bald humans with tatoos, a magical race, based on the high elves, with darkvision. All special powers come from a magical rune. They are allied of the latter basic humans.
- arabic-style humans, loosely based on the gnome, with a knack for trade and architecture. They are former slaves of the bald magical humans.
- north-american indian style humans, based on the wild elves, +5 speed, with advantage on all skills done outside.
- viking-style humans, based on the half-orc
- gipsy-type humans, based somewhat on the halfling, but with a few divination spells. They come form a far-away place, through misty regions, having travelled for generations, before landing in the Vale.
- black-skinned, bald humans that live underground, based on the hill dwarf, with double darkvision range
- black-skinned humans (with hair) that live in the mountains, cousins of the latter, based on the mountain dwarves, with no darkvision, resistance to cold, and they have advantate on their first death save (they're tough)
- the "unpure", very loosely based on the half-elves, but instead they are half of one race and half of the other, and as such they get one trait from each race of their parents, and +1 bonus to one ability score of the associated parent also (and +1 CON).
- the ones that have demonic heritage, they are of any one of the above race in appearance, but they are based on the tieflings mechanically. 500 years ago, there was a big war and some demons were let loose in the Vale where my campaigns take place, and the demons impregnated women of all races. Demonic blood still runs. Anyone found that has the birthmark of the demonic heritage is burned on a stake.
The only races with darkvision are the magical humans, the underground humans and the ones that have demonic heritage. The latter are very rare indeed in society, and they hide their true nature. So darkvision is a privilege, not a shortage that a few rare races suffer from.
I have a story for the races of course, with the mechanics being geared towards that story, how they came to the Vale where my campaigns take place, and so on. Mechanically I'd say that my races are about 50-75% identical to those of the PHB, and for the rest I removed/added stuff, but tried to keep the base race as a guideline to balance things out to some extent. I prepared a detailed book where I included a few pictures of each race, all taken from the dark fantasy genre through many searches on the internet (that's certainly a fun part for me).